drivers/video/udlfb.c

   1 /*
   2  * udlfb.c -- Framebuffer driver for DisplayLink USB controller
   3  *
   4  * Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it>
   5  * Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com>
   6  * Copyright (C) 2009 Bernie Thompson <bernie@plugable.com>
   7  *
   8  * This file is subject to the terms and conditions of the GNU General Public
   9  * License v2. See the file COPYING in the main directory of this archive for
  10  * more details.
  11  *
  12  * Layout is based on skeletonfb by James Simmons and Geert Uytterhoeven,
  13  * usb-skeleton by GregKH.
  14  *
  15  * Device-specific portions based on information from Displaylink, with work
  16  * from Florian Echtler, Henrik Bjerregaard Pedersen, and others.
  17  */
  18
  19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  20
  21 #include <linux/module.h>
  22 #include <linux/kernel.h>
  23 #include <linux/init.h>
  24 #include <linux/usb.h>
  25 #include <linux/uaccess.h>
  26 #include <linux/mm.h>
  27 #include <linux/fb.h>
  28 #include <linux/vmalloc.h>
  29 #include <linux/slab.h>
  30 #include <linux/prefetch.h>
  31 #include <linux/delay.h>
  32 #include <video/udlfb.h>
  33 #include "edid.h"
  34
  35 static struct fb_fix_screeninfo dlfb_fix = {
  36         .id =           "udlfb",
  37         .type =         FB_TYPE_PACKED_PIXELS,
  38         .visual =       FB_VISUAL_TRUECOLOR,
  39         .xpanstep =     0,
  40         .ypanstep =     0,
  41         .ywrapstep =    0,
  42         .accel =        FB_ACCEL_NONE,
  43 };
  44
  45 static const u32 udlfb_info_flags = FBINFO_DEFAULT | FBINFO_READS_FAST |
  46                 FBINFO_VIRTFB |
  47                 FBINFO_HWACCEL_IMAGEBLIT | FBINFO_HWACCEL_FILLRECT |
  48                 FBINFO_HWACCEL_COPYAREA | FBINFO_MISC_ALWAYS_SETPAR;
  49
  50 /*
  51  * There are many DisplayLink-based graphics products, all with unique PIDs.
  52  * So we match on DisplayLink's VID + Vendor-Defined Interface Class (0xff)
  53  * We also require a match on SubClass (0x00) and Protocol (0x00),
  54  * which is compatible with all known USB 2.0 era graphics chips and firmware,
  55  * but allows DisplayLink to increment those for any future incompatible chips
  56  */
  57 static struct usb_device_id id_table[] = {
  58         {.idVendor = 0x17e9,
  59          .bInterfaceClass = 0xff,
  60          .bInterfaceSubClass = 0x00,
  61          .bInterfaceProtocol = 0x00,
  62          .match_flags = USB_DEVICE_ID_MATCH_VENDOR |
  63                 USB_DEVICE_ID_MATCH_INT_CLASS |
  64                 USB_DEVICE_ID_MATCH_INT_SUBCLASS |
  65                 USB_DEVICE_ID_MATCH_INT_PROTOCOL,
  66         },
  67         {},
  68 };
  69 MODULE_DEVICE_TABLE(usb, id_table);
  70
  71 /* module options */
  72 static bool console = 1; /* Allow fbcon to open framebuffer */
  73 static bool fb_defio = 1;  /* Detect mmap writes using page faults */
  74 static bool shadow = 1; /* Optionally disable shadow framebuffer */
  75
  76 /* dlfb keeps a list of urbs for efficient bulk transfers */
  77 static void dlfb_urb_completion(struct urb *urb);
  78 static struct urb *dlfb_get_urb(struct dlfb_data *dev);
  79 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb * urb, size_t len);
  80 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size);
  81 static void dlfb_free_urb_list(struct dlfb_data *dev);
  82
  83 /*
  84  * All DisplayLink bulk operations start with 0xAF, followed by specific code
  85  * All operations are written to buffers which then later get sent to device
  86  */
  87 static char *dlfb_set_register(char *buf, u8 reg, u8 val)
  88 {
  89         *buf++ = 0xAF;
  90         *buf++ = 0x20;
  91         *buf++ = reg;
  92         *buf++ = val;
  93         return buf;
  94 }
  95
  96 static char *dlfb_vidreg_lock(char *buf)
  97 {
  98         return dlfb_set_register(buf, 0xFF, 0x00);
  99 }
 100
 101 static char *dlfb_vidreg_unlock(char *buf)
 102 {
 103         return dlfb_set_register(buf, 0xFF, 0xFF);
 104 }
 105
 106 /*
 107  * Map FB_BLANK_* to DisplayLink register
 108  * DLReg FB_BLANK_*
 109  * ----- -----------------------------
 110  *  0x00 FB_BLANK_UNBLANK (0)
 111  *  0x01 FB_BLANK (1)
 112  *  0x03 FB_BLANK_VSYNC_SUSPEND (2)
 113  *  0x05 FB_BLANK_HSYNC_SUSPEND (3)
 114  *  0x07 FB_BLANK_POWERDOWN (4) Note: requires modeset to come back
 115  */
 116 static char *dlfb_blanking(char *buf, int fb_blank)
 117 {
 118         u8 reg;
 119
 120         switch (fb_blank) {
 121         case FB_BLANK_POWERDOWN:
 122                 reg = 0x07;
 123                 break;
 124         case FB_BLANK_HSYNC_SUSPEND:
 125                 reg = 0x05;
 126                 break;
 127         case FB_BLANK_VSYNC_SUSPEND:
 128                 reg = 0x03;
 129                 break;
 130         case FB_BLANK_NORMAL:
 131                 reg = 0x01;
 132                 break;
 133         default:
 134                 reg = 0x00;
 135         }
 136
 137         buf = dlfb_set_register(buf, 0x1F, reg);
 138
 139         return buf;
 140 }
 141
 142 static char *dlfb_set_color_depth(char *buf, u8 selection)
 143 {
 144         return dlfb_set_register(buf, 0x00, selection);
 145 }
 146
 147 static char *dlfb_set_base16bpp(char *wrptr, u32 base)
 148 {
 149         /* the base pointer is 16 bits wide, 0x20 is hi byte. */
 150         wrptr = dlfb_set_register(wrptr, 0x20, base >> 16);
 151         wrptr = dlfb_set_register(wrptr, 0x21, base >> 8);
 152         return dlfb_set_register(wrptr, 0x22, base);
 153 }
 154
 155 /*
 156  * DisplayLink HW has separate 16bpp and 8bpp framebuffers.
 157  * In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer
 158  */
 159 static char *dlfb_set_base8bpp(char *wrptr, u32 base)
 160 {
 161         wrptr = dlfb_set_register(wrptr, 0x26, base >> 16);
 162         wrptr = dlfb_set_register(wrptr, 0x27, base >> 8);
 163         return dlfb_set_register(wrptr, 0x28, base);
 164 }
 165
 166 static char *dlfb_set_register_16(char *wrptr, u8 reg, u16 value)
 167 {
 168         wrptr = dlfb_set_register(wrptr, reg, value >> 8);
 169         return dlfb_set_register(wrptr, reg+1, value);
 170 }
 171
 172 /*
 173  * This is kind of weird because the controller takes some
 174  * register values in a different byte order than other registers.
 175  */
 176 static char *dlfb_set_register_16be(char *wrptr, u8 reg, u16 value)
 177 {
 178         wrptr = dlfb_set_register(wrptr, reg, value);
 179         return dlfb_set_register(wrptr, reg+1, value >> 8);
 180 }
 181
 182 /*
 183  * LFSR is linear feedback shift register. The reason we have this is
 184  * because the display controller needs to minimize the clock depth of
 185  * various counters used in the display path. So this code reverses the
 186  * provided value into the lfsr16 value by counting backwards to get
 187  * the value that needs to be set in the hardware comparator to get the
 188  * same actual count. This makes sense once you read above a couple of
 189  * times and think about it from a hardware perspective.
 190  */
 191 static u16 dlfb_lfsr16(u16 actual_count)
 192 {
 193         u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */
 194
 195         while (actual_count--) {
 196                 lv =     ((lv << 1) |
 197                         (((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1))
 198                         & 0xFFFF;
 199         }
 200
 201         return (u16) lv;
 202 }
 203
 204 /*
 205  * This does LFSR conversion on the value that is to be written.
 206  * See LFSR explanation above for more detail.
 207  */
 208 static char *dlfb_set_register_lfsr16(char *wrptr, u8 reg, u16 value)
 209 {
 210         return dlfb_set_register_16(wrptr, reg, dlfb_lfsr16(value));
 211 }
 212
 213 /*
 214  * This takes a standard fbdev screeninfo struct and all of its monitor mode
 215  * details and converts them into the DisplayLink equivalent register commands.
 216  */
 217 static char *dlfb_set_vid_cmds(char *wrptr, struct fb_var_screeninfo *var)
 218 {
 219         u16 xds, yds;
 220         u16 xde, yde;
 221         u16 yec;
 222
 223         /* x display start */
 224         xds = var->left_margin + var->hsync_len;
 225         wrptr = dlfb_set_register_lfsr16(wrptr, 0x01, xds);
 226         /* x display end */
 227         xde = xds + var->xres;
 228         wrptr = dlfb_set_register_lfsr16(wrptr, 0x03, xde);
 229
 230         /* y display start */
 231         yds = var->upper_margin + var->vsync_len;
 232         wrptr = dlfb_set_register_lfsr16(wrptr, 0x05, yds);
 233         /* y display end */
 234         yde = yds + var->yres;
 235         wrptr = dlfb_set_register_lfsr16(wrptr, 0x07, yde);
 236
 237         /* x end count is active + blanking - 1 */
 238         wrptr = dlfb_set_register_lfsr16(wrptr, 0x09,
 239                         xde + var->right_margin - 1);
 240
 241         /* libdlo hardcodes hsync start to 1 */
 242         wrptr = dlfb_set_register_lfsr16(wrptr, 0x0B, 1);
 243
 244         /* hsync end is width of sync pulse + 1 */
 245         wrptr = dlfb_set_register_lfsr16(wrptr, 0x0D, var->hsync_len + 1);
 246
 247         /* hpixels is active pixels */
 248         wrptr = dlfb_set_register_16(wrptr, 0x0F, var->xres);
 249
 250         /* yendcount is vertical active + vertical blanking */
 251         yec = var->yres + var->upper_margin + var->lower_margin +
 252                         var->vsync_len;
 253         wrptr = dlfb_set_register_lfsr16(wrptr, 0x11, yec);
 254
 255         /* libdlo hardcodes vsync start to 0 */
 256         wrptr = dlfb_set_register_lfsr16(wrptr, 0x13, 0);
 257
 258         /* vsync end is width of vsync pulse */
 259         wrptr = dlfb_set_register_lfsr16(wrptr, 0x15, var->vsync_len);
 260
 261         /* vpixels is active pixels */
 262         wrptr = dlfb_set_register_16(wrptr, 0x17, var->yres);
 263
 264         /* convert picoseconds to 5kHz multiple for pclk5k = x * 1E12/5k */
 265         wrptr = dlfb_set_register_16be(wrptr, 0x1B,
 266                         200*1000*1000/var->pixclock);
 267
 268         return wrptr;
 269 }
 270
 271 /*
 272  * This takes a standard fbdev screeninfo struct that was fetched or prepared
 273  * and then generates the appropriate command sequence that then drives the
 274  * display controller.
 275  */
 276 static int dlfb_set_video_mode(struct dlfb_data *dev,
 277                                 struct fb_var_screeninfo *var)
 278 {
 279         char *buf;
 280         char *wrptr;
 281         int retval = 0;
 282         int writesize;
 283         struct urb *urb;
 284
 285         if (!atomic_read(&dev->usb_active))
 286                 return -EPERM;
 287
 288         urb = dlfb_get_urb(dev);
 289         if (!urb)
 290                 return -ENOMEM;
 291
 292         buf = (char *) urb->transfer_buffer;
 293
 294         /*
 295         * This first section has to do with setting the base address on the
 296         * controller * associated with the display. There are 2 base
 297         * pointers, currently, we only * use the 16 bpp segment.
 298         */
 299         wrptr = dlfb_vidreg_lock(buf);
 300         wrptr = dlfb_set_color_depth(wrptr, 0x00);
 301         /* set base for 16bpp segment to 0 */
 302         wrptr = dlfb_set_base16bpp(wrptr, 0);
 303         /* set base for 8bpp segment to end of fb */
 304         wrptr = dlfb_set_base8bpp(wrptr, dev->info->fix.smem_len);
 305
 306         wrptr = dlfb_set_vid_cmds(wrptr, var);
 307         wrptr = dlfb_blanking(wrptr, FB_BLANK_UNBLANK);
 308         wrptr = dlfb_vidreg_unlock(wrptr);
 309
 310         writesize = wrptr - buf;
 311
 312         retval = dlfb_submit_urb(dev, urb, writesize);
 313
 314         dev->blank_mode = FB_BLANK_UNBLANK;
 315
 316         return retval;
 317 }
 318
 319 static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma)
 320 {
 321         unsigned long start = vma->vm_start;
 322         unsigned long size = vma->vm_end - vma->vm_start;
 323         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 324         unsigned long page, pos;
 325
 326         if (offset + size > info->fix.smem_len)
 327                 return -EINVAL;
 328
 329         pos = (unsigned long)info->fix.smem_start + offset;
 330
 331         pr_notice("mmap() framebuffer addr:%lu size:%lu\n",
 332                   pos, size);
 333
 334         while (size > 0) {
 335                 page = vmalloc_to_pfn((void *)pos);
 336                 if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED))
 337                         return -EAGAIN;
 338
 339                 start += PAGE_SIZE;
 340                 pos += PAGE_SIZE;
 341                 if (size > PAGE_SIZE)
 342                         size -= PAGE_SIZE;
 343                 else
 344                         size = 0;
 345         }
 346
 347         vma->vm_flags |= VM_RESERVED;   /* avoid to swap out this VMA */
 348         return 0;
 349 }
 350
 351 /*
 352  * Trims identical data from front and back of line
 353  * Sets new front buffer address and width
 354  * And returns byte count of identical pixels
 355  * Assumes CPU natural alignment (unsigned long)
 356  * for back and front buffer ptrs and width
 357  */
 358 static int dlfb_trim_hline(const u8 *bback, const u8 **bfront, int *width_bytes)
 359 {
 360         int j, k;
 361         const unsigned long *back = (const unsigned long *) bback;
 362         const unsigned long *front = (const unsigned long *) *bfront;
 363         const int width = *width_bytes / sizeof(unsigned long);
 364         int identical = width;
 365         int start = width;
 366         int end = width;
 367
 368         prefetch((void *) front);
 369         prefetch((void *) back);
 370
 371         for (j = 0; j < width; j++) {
 372                 if (back[j] != front[j]) {
 373                         start = j;
 374                         break;
 375                 }
 376         }
 377
 378         for (k = width - 1; k > j; k--) {
 379                 if (back[k] != front[k]) {
 380                         end = k+1;
 381                         break;
 382                 }
 383         }
 384
 385         identical = start + (width - end);
 386         *bfront = (u8 *) &front[start];
 387         *width_bytes = (end - start) * sizeof(unsigned long);
 388
 389         return identical * sizeof(unsigned long);
 390 }
 391
 392 /*
 393  * Render a command stream for an encoded horizontal line segment of pixels.
 394  *
 395  * A command buffer holds several commands.
 396  * It always begins with a fresh command header
 397  * (the protocol doesn't require this, but we enforce it to allow
 398  * multiple buffers to be potentially encoded and sent in parallel).
 399  * A single command encodes one contiguous horizontal line of pixels
 400  *
 401  * The function relies on the client to do all allocation, so that
 402  * rendering can be done directly to output buffers (e.g. USB URBs).
 403  * The function fills the supplied command buffer, providing information
 404  * on where it left off, so the client may call in again with additional
 405  * buffers if the line will take several buffers to complete.
 406  *
 407  * A single command can transmit a maximum of 256 pixels,
 408  * regardless of the compression ratio (protocol design limit).
 409  * To the hardware, 0 for a size byte means 256
 410  *
 411  * Rather than 256 pixel commands which are either rl or raw encoded,
 412  * the rlx command simply assumes alternating raw and rl spans within one cmd.
 413  * This has a slightly larger header overhead, but produces more even results.
 414  * It also processes all data (read and write) in a single pass.
 415  * Performance benchmarks of common cases show it having just slightly better
 416  * compression than 256 pixel raw or rle commands, with similar CPU consumpion.
 417  * But for very rl friendly data, will compress not quite as well.
 418  */
 419 static void dlfb_compress_hline(
 420         const uint16_t **pixel_start_ptr,
 421         const uint16_t *const pixel_end,
 422         uint32_t *device_address_ptr,
 423         uint8_t **command_buffer_ptr,
 424         const uint8_t *const cmd_buffer_end)
 425 {
 426         const uint16_t *pixel = *pixel_start_ptr;
 427         uint32_t dev_addr  = *device_address_ptr;
 428         uint8_t *cmd = *command_buffer_ptr;
 429         const int bpp = 2;
 430
 431         while ((pixel_end > pixel) &&
 432                (cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) {
 433                 uint8_t *raw_pixels_count_byte = 0;
 434                 uint8_t *cmd_pixels_count_byte = 0;
 435                 const uint16_t *raw_pixel_start = 0;
 436                 const uint16_t *cmd_pixel_start, *cmd_pixel_end = 0;
 437
 438                 prefetchw((void *) cmd); /* pull in one cache line at least */
 439
 440                 *cmd++ = 0xAF;
 441                 *cmd++ = 0x6B;
 442                 *cmd++ = (uint8_t) ((dev_addr >> 16) & 0xFF);
 443                 *cmd++ = (uint8_t) ((dev_addr >> 8) & 0xFF);
 444                 *cmd++ = (uint8_t) ((dev_addr) & 0xFF);
 445
 446                 cmd_pixels_count_byte = cmd++; /*  we'll know this later */
 447                 cmd_pixel_start = pixel;
 448
 449                 raw_pixels_count_byte = cmd++; /*  we'll know this later */
 450                 raw_pixel_start = pixel;
 451
 452                 cmd_pixel_end = pixel + min(MAX_CMD_PIXELS + 1,
 453                         min((int)(pixel_end - pixel),
 454                             (int)(cmd_buffer_end - cmd) / bpp));
 455
 456                 prefetch_range((void *) pixel, (cmd_pixel_end - pixel) * bpp);
 457
 458                 while (pixel < cmd_pixel_end) {
 459                         const uint16_t * const repeating_pixel = pixel;
 460
 461                         *(uint16_t *)cmd = cpu_to_be16p(pixel);
 462                         cmd += 2;
 463                         pixel++;
 464
 465                         if (unlikely((pixel < cmd_pixel_end) &&
 466                                      (*pixel == *repeating_pixel))) {
 467                                 /* go back and fill in raw pixel count */
 468                                 *raw_pixels_count_byte = ((repeating_pixel -
 469                                                 raw_pixel_start) + 1) & 0xFF;
 470
 471                                 while ((pixel < cmd_pixel_end)
 472                                        && (*pixel == *repeating_pixel)) {
 473                                         pixel++;
 474                                 }
 475
 476                                 /* immediately after raw data is repeat byte */
 477                                 *cmd++ = ((pixel - repeating_pixel) - 1) & 0xFF;
 478
 479                                 /* Then start another raw pixel span */
 480                                 raw_pixel_start = pixel;
 481                                 raw_pixels_count_byte = cmd++;
 482                         }
 483                 }
 484
 485                 if (pixel > raw_pixel_start) {
 486                         /* finalize last RAW span */
 487                         *raw_pixels_count_byte = (pixel-raw_pixel_start) & 0xFF;
 488                 }
 489
 490                 *cmd_pixels_count_byte = (pixel - cmd_pixel_start) & 0xFF;
 491                 dev_addr += (pixel - cmd_pixel_start) * bpp;
 492         }
 493
 494         if (cmd_buffer_end <= MIN_RLX_CMD_BYTES + cmd) {
 495                 /* Fill leftover bytes with no-ops */
 496                 if (cmd_buffer_end > cmd)
 497                         memset(cmd, 0xAF, cmd_buffer_end - cmd);
 498                 cmd = (uint8_t *) cmd_buffer_end;
 499         }
 500
 501         *command_buffer_ptr = cmd;
 502         *pixel_start_ptr = pixel;
 503         *device_address_ptr = dev_addr;
 504
 505         return;
 506 }
 507
 508 /*
 509  * There are 3 copies of every pixel: The front buffer that the fbdev
 510  * client renders to, the actual framebuffer across the USB bus in hardware
 511  * (that we can only write to, slowly, and can never read), and (optionally)
 512  * our shadow copy that tracks what's been sent to that hardware buffer.
 513  */
 514 static int dlfb_render_hline(struct dlfb_data *dev, struct urb **urb_ptr,
 515                               const char *front, char **urb_buf_ptr,
 516                               u32 byte_offset, u32 byte_width,
 517                               int *ident_ptr, int *sent_ptr)
 518 {
 519         const u8 *line_start, *line_end, *next_pixel;
 520         u32 dev_addr = dev->base16 + byte_offset;
 521         struct urb *urb = *urb_ptr;
 522         u8 *cmd = *urb_buf_ptr;
 523         u8 *cmd_end = (u8 *) urb->transfer_buffer + urb->transfer_buffer_length;
 524
 525         line_start = (u8 *) (front + byte_offset);
 526         next_pixel = line_start;
 527         line_end = next_pixel + byte_width;
 528
 529         if (dev->backing_buffer) {
 530                 int offset;
 531                 const u8 *back_start = (u8 *) (dev->backing_buffer
 532                                                 + byte_offset);
 533
 534                 *ident_ptr += dlfb_trim_hline(back_start, &next_pixel,
 535                         &byte_width);
 536
 537                 offset = next_pixel - line_start;
 538                 line_end = next_pixel + byte_width;
 539                 dev_addr += offset;
 540                 back_start += offset;
 541                 line_start += offset;
 542
 543                 memcpy((char *)back_start, (char *) line_start,
 544                        byte_width);
 545         }
 546
 547         while (next_pixel < line_end) {
 548
 549                 dlfb_compress_hline((const uint16_t **) &next_pixel,
 550                              (const uint16_t *) line_end, &dev_addr,
 551                         (u8 **) &cmd, (u8 *) cmd_end);
 552
 553                 if (cmd >= cmd_end) {
 554                         int len = cmd - (u8 *) urb->transfer_buffer;
 555                         if (dlfb_submit_urb(dev, urb, len))
 556                                 return 1; /* lost pixels is set */
 557                         *sent_ptr += len;
 558                         urb = dlfb_get_urb(dev);
 559                         if (!urb)
 560                                 return 1; /* lost_pixels is set */
 561                         *urb_ptr = urb;
 562                         cmd = urb->transfer_buffer;
 563                         cmd_end = &cmd[urb->transfer_buffer_length];
 564                 }
 565         }
 566
 567         *urb_buf_ptr = cmd;
 568
 569         return 0;
 570 }
 571
 572 int dlfb_handle_damage(struct dlfb_data *dev, int x, int y,
 573                int width, int height, char *data)
 574 {
 575         int i, ret;
 576         char *cmd;
 577         cycles_t start_cycles, end_cycles;
 578         int bytes_sent = 0;
 579         int bytes_identical = 0;
 580         struct urb *urb;
 581         int aligned_x;
 582
 583         start_cycles = get_cycles();
 584
 585         aligned_x = DL_ALIGN_DOWN(x, sizeof(unsigned long));
 586         width = DL_ALIGN_UP(width + (x-aligned_x), sizeof(unsigned long));
 587         x = aligned_x;
 588
 589         if ((width <= 0) ||
 590             (x + width > dev->info->var.xres) ||
 591             (y + height > dev->info->var.yres))
 592                 return -EINVAL;
 593
 594         if (!atomic_read(&dev->usb_active))
 595                 return 0;
 596
 597         urb = dlfb_get_urb(dev);
 598         if (!urb)
 599                 return 0;
 600         cmd = urb->transfer_buffer;
 601
 602         for (i = y; i < y + height ; i++) {
 603                 const int line_offset = dev->info->fix.line_length * i;
 604                 const int byte_offset = line_offset + (x * BPP);
 605
 606                 if (dlfb_render_hline(dev, &urb,
 607                                       (char *) dev->info->fix.smem_start,
 608                                       &cmd, byte_offset, width * BPP,
 609                                       &bytes_identical, &bytes_sent))
 610                         goto error;
 611         }
 612
 613         if (cmd > (char *) urb->transfer_buffer) {
 614                 /* Send partial buffer remaining before exiting */
 615                 int len = cmd - (char *) urb->transfer_buffer;
 616                 ret = dlfb_submit_urb(dev, urb, len);
 617                 bytes_sent += len;
 618         } else
 619                 dlfb_urb_completion(urb);
 620
 621 error:
 622         atomic_add(bytes_sent, &dev->bytes_sent);
 623         atomic_add(bytes_identical, &dev->bytes_identical);
 624         atomic_add(width*height*2, &dev->bytes_rendered);
 625         end_cycles = get_cycles();
 626         atomic_add(((unsigned int) ((end_cycles - start_cycles)
 627                     >> 10)), /* Kcycles */
 628                    &dev->cpu_kcycles_used);
 629
 630         return 0;
 631 }
 632
 633 /*
 634  * Path triggered by usermode clients who write to filesystem
 635  * e.g. cat filename > /dev/fb1
 636  * Not used by X Windows or text-mode console. But useful for testing.
 637  * Slow because of extra copy and we must assume all pixels dirty.
 638  */
 639 static ssize_t dlfb_ops_write(struct fb_info *info, const char __user *buf,
 640                           size_t count, loff_t *ppos)
 641 {
 642         ssize_t result;
 643         struct dlfb_data *dev = info->par;
 644         u32 offset = (u32) *ppos;
 645
 646         result = fb_sys_write(info, buf, count, ppos);
 647
 648         if (result > 0) {
 649                 int start = max((int)(offset / info->fix.line_length) - 1, 0);
 650                 int lines = min((u32)((result / info->fix.line_length) + 1),
 651                                 (u32)info->var.yres);
 652
 653                 dlfb_handle_damage(dev, 0, start, info->var.xres,
 654                         lines, info->screen_base);
 655         }
 656
 657         return result;
 658 }
 659
 660 /* hardware has native COPY command (see libdlo), but not worth it for fbcon */
 661 static void dlfb_ops_copyarea(struct fb_info *info,
 662                                 const struct fb_copyarea *area)
 663 {
 664
 665         struct dlfb_data *dev = info->par;
 666
 667         sys_copyarea(info, area);
 668
 669         dlfb_handle_damage(dev, area->dx, area->dy,
 670                         area->width, area->height, info->screen_base);
 671 }
 672
 673 static void dlfb_ops_imageblit(struct fb_info *info,
 674                                 const struct fb_image *image)
 675 {
 676         struct dlfb_data *dev = info->par;
 677
 678         sys_imageblit(info, image);
 679
 680         dlfb_handle_damage(dev, image->dx, image->dy,
 681                         image->width, image->height, info->screen_base);
 682 }
 683
 684 static void dlfb_ops_fillrect(struct fb_info *info,
 685                           const struct fb_fillrect *rect)
 686 {
 687         struct dlfb_data *dev = info->par;
 688
 689         sys_fillrect(info, rect);
 690
 691         dlfb_handle_damage(dev, rect->dx, rect->dy, rect->width,
 692                               rect->height, info->screen_base);
 693 }
 694
 695 /*
 696  * NOTE: fb_defio.c is holding info->fbdefio.mutex
 697  *   Touching ANY framebuffer memory that triggers a page fault
 698  *   in fb_defio will cause a deadlock, when it also tries to
 699  *   grab the same mutex.
 700  */
 701 static void dlfb_dpy_deferred_io(struct fb_info *info,
 702                                 struct list_head *pagelist)
 703 {
 704         struct page *cur;
 705         struct fb_deferred_io *fbdefio = info->fbdefio;
 706         struct dlfb_data *dev = info->par;
 707         struct urb *urb;
 708         char *cmd;
 709         cycles_t start_cycles, end_cycles;
 710         int bytes_sent = 0;
 711         int bytes_identical = 0;
 712         int bytes_rendered = 0;
 713
 714         if (!fb_defio)
 715                 return;
 716
 717         if (!atomic_read(&dev->usb_active))
 718                 return;
 719
 720         start_cycles = get_cycles();
 721
 722         urb = dlfb_get_urb(dev);
 723         if (!urb)
 724                 return;
 725
 726         cmd = urb->transfer_buffer;
 727
 728         /* walk the written page list and render each to device */
 729         list_for_each_entry(cur, &fbdefio->pagelist, lru) {
 730
 731                 if (dlfb_render_hline(dev, &urb, (char *) info->fix.smem_start,
 732                                   &cmd, cur->index << PAGE_SHIFT,
 733                                   PAGE_SIZE, &bytes_identical, &bytes_sent))
 734                         goto error;
 735                 bytes_rendered += PAGE_SIZE;
 736         }
 737
 738         if (cmd > (char *) urb->transfer_buffer) {
 739                 /* Send partial buffer remaining before exiting */
 740                 int len = cmd - (char *) urb->transfer_buffer;
 741                 dlfb_submit_urb(dev, urb, len);
 742                 bytes_sent += len;
 743         } else
 744                 dlfb_urb_completion(urb);
 745
 746 error:
 747         atomic_add(bytes_sent, &dev->bytes_sent);
 748         atomic_add(bytes_identical, &dev->bytes_identical);
 749         atomic_add(bytes_rendered, &dev->bytes_rendered);
 750         end_cycles = get_cycles();
 751         atomic_add(((unsigned int) ((end_cycles - start_cycles)
 752                     >> 10)), /* Kcycles */
 753                    &dev->cpu_kcycles_used);
 754 }
 755
 756 static int dlfb_get_edid(struct dlfb_data *dev, char *edid, int len)
 757 {
 758         int i;
 759         int ret;
 760         char *rbuf;
 761
 762         rbuf = kmalloc(2, GFP_KERNEL);
 763         if (!rbuf)
 764                 return 0;
 765
 766         for (i = 0; i < len; i++) {
 767                 ret = usb_control_msg(dev->udev,
 768                                     usb_rcvctrlpipe(dev->udev, 0), (0x02),
 769                                     (0x80 | (0x02 << 5)), i << 8, 0xA1, rbuf, 2,
 770                                     HZ);
 771                 if (ret < 1) {
 772                         pr_err("Read EDID byte %d failed err %x\n", i, ret);
 773                         i--;
 774                         break;
 775                 }
 776                 edid[i] = rbuf[1];
 777         }
 778
 779         kfree(rbuf);
 780
 781         return i;
 782 }
 783
 784 static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd,
 785                                 unsigned long arg)
 786 {
 787
 788         struct dlfb_data *dev = info->par;
 789
 790         if (!atomic_read(&dev->usb_active))
 791                 return 0;
 792
 793         /* TODO: Update X server to get this from sysfs instead */
 794         if (cmd == DLFB_IOCTL_RETURN_EDID) {
 795                 void __user *edid = (void __user *)arg;
 796                 if (copy_to_user(edid, dev->edid, dev->edid_size))
 797                         return -EFAULT;
 798                 return 0;
 799         }
 800
 801         /* TODO: Help propose a standard fb.h ioctl to report mmap damage */
 802         if (cmd == DLFB_IOCTL_REPORT_DAMAGE) {
 803                 struct dloarea area;
 804
 805                 if (copy_from_user(&area, (void __user *)arg,
 806                                   sizeof(struct dloarea)))
 807                         return -EFAULT;
 808
 809                 /*
 810                  * If we have a damage-aware client, turn fb_defio "off"
 811                  * To avoid perf imact of unnecessary page fault handling.
 812                  * Done by resetting the delay for this fb_info to a very
 813                  * long period. Pages will become writable and stay that way.
 814                  * Reset to normal value when all clients have closed this fb.
 815                  */
 816                 if (info->fbdefio)
 817                         info->fbdefio->delay = DL_DEFIO_WRITE_DISABLE;
 818
 819                 if (area.x < 0)
 820                         area.x = 0;
 821
 822                 if (area.x > info->var.xres)
 823                         area.x = info->var.xres;
 824
 825                 if (area.y < 0)
 826                         area.y = 0;
 827
 828                 if (area.y > info->var.yres)
 829                         area.y = info->var.yres;
 830
 831                 dlfb_handle_damage(dev, area.x, area.y, area.w, area.h,
 832                            info->screen_base);
 833         }
 834
 835         return 0;
 836 }
 837
 838 /* taken from vesafb */
 839 static int
 840 dlfb_ops_setcolreg(unsigned regno, unsigned red, unsigned green,
 841                unsigned blue, unsigned transp, struct fb_info *info)
 842 {
 843         int err = 0;
 844
 845         if (regno >= info->cmap.len)
 846                 return 1;
 847
 848         if (regno < 16) {
 849                 if (info->var.red.offset == 10) {
 850                         /* 1:5:5:5 */
 851                         ((u32 *) (info->pseudo_palette))[regno] =
 852                             ((red & 0xf800) >> 1) |
 853                             ((green & 0xf800) >> 6) | ((blue & 0xf800) >> 11);
 854                 } else {
 855                         /* 0:5:6:5 */
 856                         ((u32 *) (info->pseudo_palette))[regno] =
 857                             ((red & 0xf800)) |
 858                             ((green & 0xfc00) >> 5) | ((blue & 0xf800) >> 11);
 859                 }
 860         }
 861
 862         return err;
 863 }
 864
 865 /*
 866  * It's common for several clients to have framebuffer open simultaneously.
 867  * e.g. both fbcon and X. Makes things interesting.
 868  * Assumes caller is holding info->lock (for open and release at least)
 869  */
 870 static int dlfb_ops_open(struct fb_info *info, int user)
 871 {
 872         struct dlfb_data *dev = info->par;
 873
 874         /*
 875          * fbcon aggressively connects to first framebuffer it finds,
 876          * preventing other clients (X) from working properly. Usually
 877          * not what the user wants. Fail by default with option to enable.
 878          */
 879         if ((user == 0) && (!console))
 880                 return -EBUSY;
 881
 882         /* If the USB device is gone, we don't accept new opens */
 883         if (dev->virtualized)
 884                 return -ENODEV;
 885
 886         dev->fb_count++;
 887
 888         kref_get(&dev->kref);
 889
 890         if (fb_defio && (info->fbdefio == NULL)) {
 891                 /* enable defio at last moment if not disabled by client */
 892
 893                 struct fb_deferred_io *fbdefio;
 894
 895                 fbdefio = kmalloc(sizeof(struct fb_deferred_io), GFP_KERNEL);
 896
 897                 if (fbdefio) {
 898                         fbdefio->delay = DL_DEFIO_WRITE_DELAY;
 899                         fbdefio->deferred_io = dlfb_dpy_deferred_io;
 900                 }
 901
 902                 info->fbdefio = fbdefio;
 903                 fb_deferred_io_init(info);
 904         }
 905
 906         pr_notice("open /dev/fb%d user=%d fb_info=%p count=%d\n",
 907             info->node, user, info, dev->fb_count);
 908
 909         return 0;
 910 }
 911
 912 /*
 913  * Called when all client interfaces to start transactions have been disabled,
 914  * and all references to our device instance (dlfb_data) are released.
 915  * Every transaction must have a reference, so we know are fully spun down
 916  */
 917 static void dlfb_free(struct kref *kref)
 918 {
 919         struct dlfb_data *dev = container_of(kref, struct dlfb_data, kref);
 920
 921         /* this function will wait for all in-flight urbs to complete */
 922         if (dev->urbs.count > 0)
 923                 dlfb_free_urb_list(dev);
 924
 925         if (dev->backing_buffer)
 926                 vfree(dev->backing_buffer);
 927
 928         kfree(dev->edid);
 929
 930         pr_warn("freeing dlfb_data %p\n", dev);
 931
 932         kfree(dev);
 933 }
 934
 935 static void dlfb_release_urb_work(struct work_struct *work)
 936 {
 937         struct urb_node *unode = container_of(work, struct urb_node,
 938                                               release_urb_work.work);
 939
 940         up(&unode->dev->urbs.limit_sem);
 941 }
 942
 943 static void dlfb_free_framebuffer_work(struct work_struct *work)
 944 {
 945         struct dlfb_data *dev = container_of(work, struct dlfb_data,
 946                                              free_framebuffer_work.work);
 947         struct fb_info *info = dev->info;
 948         int node = info->node;
 949
 950         unregister_framebuffer(info);
 951
 952         if (info->cmap.len != 0)
 953                 fb_dealloc_cmap(&info->cmap);
 954         if (info->monspecs.modedb)
 955                 fb_destroy_modedb(info->monspecs.modedb);
 956         if (info->screen_base)
 957                 vfree(info->screen_base);
 958
 959         fb_destroy_modelist(&info->modelist);
 960
 961         dev->info = 0;
 962
 963         /* Assume info structure is freed after this point */
 964         framebuffer_release(info);
 965
 966         pr_warn("fb_info for /dev/fb%d has been freed\n", node);
 967
 968         /* ref taken in probe() as part of registering framebfufer */
 969         kref_put(&dev->kref, dlfb_free);
 970 }
 971
 972 /*
 973  * Assumes caller is holding info->lock mutex (for open and release at least)
 974  */
 975 static int dlfb_ops_release(struct fb_info *info, int user)
 976 {
 977         struct dlfb_data *dev = info->par;
 978
 979         dev->fb_count--;
 980
 981         /* We can't free fb_info here - fbmem will touch it when we return */
 982         if (dev->virtualized && (dev->fb_count == 0))
 983                 schedule_delayed_work(&dev->free_framebuffer_work, HZ);
 984
 985         if ((dev->fb_count == 0) && (info->fbdefio)) {
 986                 fb_deferred_io_cleanup(info);
 987                 kfree(info->fbdefio);
 988                 info->fbdefio = NULL;
 989                 info->fbops->fb_mmap = dlfb_ops_mmap;
 990         }
 991
 992         pr_warn("released /dev/fb%d user=%d count=%d\n",
 993                   info->node, user, dev->fb_count);
 994
 995         kref_put(&dev->kref, dlfb_free);
 996
 997         return 0;
 998 }
 999
1000 /*
1001  * Check whether a video mode is supported by the DisplayLink chip
1002  * We start from monitor's modes, so don't need to filter that here
1003  */
1004 static int dlfb_is_valid_mode(struct fb_videomode *mode,
1005                 struct fb_info *info)
1006 {
1007         struct dlfb_data *dev = info->par;
1008
1009         if (mode->xres * mode->yres > dev->sku_pixel_limit) {
1010                 pr_warn("%dx%d beyond chip capabilities\n",
1011                        mode->xres, mode->yres);
1012                 return 0;
1013         }
1014
1015         pr_info("%dx%d @ %d Hz valid mode\n", mode->xres, mode->yres,
1016                 mode->refresh);
1017
1018         return 1;
1019 }
1020
1021 static void dlfb_var_color_format(struct fb_var_screeninfo *var)
1022 {
1023         const struct fb_bitfield red = { 11, 5, 0 };
1024         const struct fb_bitfield green = { 5, 6, 0 };
1025         const struct fb_bitfield blue = { 0, 5, 0 };
1026
1027         var->bits_per_pixel = 16;
1028         var->red = red;
1029         var->green = green;
1030         var->blue = blue;
1031 }
1032
1033 static int dlfb_ops_check_var(struct fb_var_screeninfo *var,
1034                                 struct fb_info *info)
1035 {
1036         struct fb_videomode mode;
1037
1038         /* TODO: support dynamically changing framebuffer size */
1039         if ((var->xres * var->yres * 2) > info->fix.smem_len)
1040                 return -EINVAL;
1041
1042         /* set device-specific elements of var unrelated to mode */
1043         dlfb_var_color_format(var);
1044
1045         fb_var_to_videomode(&mode, var);
1046
1047         if (!dlfb_is_valid_mode(&mode, info))
1048                 return -EINVAL;
1049
1050         return 0;
1051 }
1052
1053 static int dlfb_ops_set_par(struct fb_info *info)
1054 {
1055         struct dlfb_data *dev = info->par;
1056         int result;
1057         u16 *pix_framebuffer;
1058         int i;
1059
1060         pr_notice("set_par mode %dx%d\n", info->var.xres, info->var.yres);
1061
1062         result = dlfb_set_video_mode(dev, &info->var);
1063
1064         if ((result == 0) && (dev->fb_count == 0)) {
1065
1066                 /* paint greenscreen */
1067
1068                 pix_framebuffer = (u16 *) info->screen_base;
1069                 for (i = 0; i < info->fix.smem_len / 2; i++)
1070                         pix_framebuffer[i] = 0x37e6;
1071
1072                 dlfb_handle_damage(dev, 0, 0, info->var.xres, info->var.yres,
1073                                    info->screen_base);
1074         }
1075
1076         return result;
1077 }
1078
1079 /* To fonzi the jukebox (e.g. make blanking changes take effect) */
1080 static char *dlfb_dummy_render(char *buf)
1081 {
1082         *buf++ = 0xAF;
1083         *buf++ = 0x6A; /* copy */
1084         *buf++ = 0x00; /* from address*/
1085         *buf++ = 0x00;
1086         *buf++ = 0x00;
1087         *buf++ = 0x01; /* one pixel */
1088         *buf++ = 0x00; /* to address */
1089         *buf++ = 0x00;
1090         *buf++ = 0x00;
1091         return buf;
1092 }
1093
1094 /*
1095  * In order to come back from full DPMS off, we need to set the mode again
1096  */
1097 static int dlfb_ops_blank(int blank_mode, struct fb_info *info)
1098 {
1099         struct dlfb_data *dev = info->par;
1100         char *bufptr;
1101         struct urb *urb;
1102
1103         pr_info("/dev/fb%d FB_BLANK mode %d --> %d\n",
1104                 info->node, dev->blank_mode, blank_mode);
1105
1106         if ((dev->blank_mode == FB_BLANK_POWERDOWN) &&
1107             (blank_mode != FB_BLANK_POWERDOWN)) {
1108
1109                 /* returning from powerdown requires a fresh modeset */
1110                 dlfb_set_video_mode(dev, &info->var);
1111         }
1112
1113         urb = dlfb_get_urb(dev);
1114         if (!urb)
1115                 return 0;
1116
1117         bufptr = (char *) urb->transfer_buffer;
1118         bufptr = dlfb_vidreg_lock(bufptr);
1119         bufptr = dlfb_blanking(bufptr, blank_mode);
1120         bufptr = dlfb_vidreg_unlock(bufptr);
1121
1122         /* seems like a render op is needed to have blank change take effect */
1123         bufptr = dlfb_dummy_render(bufptr);
1124
1125         dlfb_submit_urb(dev, urb, bufptr -
1126                         (char *) urb->transfer_buffer);
1127
1128         dev->blank_mode = blank_mode;
1129
1130         return 0;
1131 }
1132
1133 static struct fb_ops dlfb_ops = {
1134         .owner = THIS_MODULE,
1135         .fb_read = fb_sys_read,
1136         .fb_write = dlfb_ops_write,
1137         .fb_setcolreg = dlfb_ops_setcolreg,
1138         .fb_fillrect = dlfb_ops_fillrect,
1139         .fb_copyarea = dlfb_ops_copyarea,
1140         .fb_imageblit = dlfb_ops_imageblit,
1141         .fb_mmap = dlfb_ops_mmap,
1142         .fb_ioctl = dlfb_ops_ioctl,
1143         .fb_open = dlfb_ops_open,
1144         .fb_release = dlfb_ops_release,
1145         .fb_blank = dlfb_ops_blank,
1146         .fb_check_var = dlfb_ops_check_var,
1147         .fb_set_par = dlfb_ops_set_par,
1148 };
1149
1150
1151 /*
1152  * Assumes &info->lock held by caller
1153  * Assumes no active clients have framebuffer open
1154  */
1155 static int dlfb_realloc_framebuffer(struct dlfb_data *dev, struct fb_info *info)
1156 {
1157         int retval = -ENOMEM;
1158         int old_len = info->fix.smem_len;
1159         int new_len;
1160         unsigned char *old_fb = info->screen_base;
1161         unsigned char *new_fb;
1162         unsigned char *new_back = 0;
1163
1164         pr_warn("Reallocating framebuffer. Addresses will change!\n");
1165
1166         new_len = info->fix.line_length * info->var.yres;
1167
1168         if (PAGE_ALIGN(new_len) > old_len) {
1169                 /*
1170                  * Alloc system memory for virtual framebuffer
1171                  */
1172                 new_fb = vmalloc(new_len);
1173                 if (!new_fb) {
1174                         pr_err("Virtual framebuffer alloc failed\n");
1175                         goto error;
1176                 }
1177
1178                 if (info->screen_base) {
1179                         memcpy(new_fb, old_fb, old_len);
1180                         vfree(info->screen_base);
1181                 }
1182
1183                 info->screen_base = new_fb;
1184                 info->fix.smem_len = PAGE_ALIGN(new_len);
1185                 info->fix.smem_start = (unsigned long) new_fb;
1186                 info->flags = udlfb_info_flags;
1187
1188                 /*
1189                  * Second framebuffer copy to mirror the framebuffer state
1190                  * on the physical USB device. We can function without this.
1191                  * But with imperfect damage info we may send pixels over USB
1192                  * that were, in fact, unchanged - wasting limited USB bandwidth
1193                  */
1194                 if (shadow)
1195                         new_back = vzalloc(new_len);
1196                 if (!new_back)
1197                         pr_info("No shadow/backing buffer allocated\n");
1198                 else {
1199                         if (dev->backing_buffer)
1200                                 vfree(dev->backing_buffer);
1201                         dev->backing_buffer = new_back;
1202                 }
1203         }
1204
1205         retval = 0;
1206
1207 error:
1208         return retval;
1209 }
1210
1211 /*
1212  * 1) Get EDID from hw, or use sw default
1213  * 2) Parse into various fb_info structs
1214  * 3) Allocate virtual framebuffer memory to back highest res mode
1215  *
1216  * Parses EDID into three places used by various parts of fbdev:
1217  * fb_var_screeninfo contains the timing of the monitor's preferred mode
1218  * fb_info.monspecs is full parsed EDID info, including monspecs.modedb
1219  * fb_info.modelist is a linked list of all monitor & VESA modes which work
1220  *
1221  * If EDID is not readable/valid, then modelist is all VESA modes,
1222  * monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode
1223  * Returns 0 if successful
1224  */
1225 static int dlfb_setup_modes(struct dlfb_data *dev,
1226                            struct fb_info *info,
1227                            char *default_edid, size_t default_edid_size)
1228 {
1229         int i;
1230         const struct fb_videomode *default_vmode = NULL;
1231         int result = 0;
1232         char *edid;
1233         int tries = 3;
1234
1235         if (info->dev) /* only use mutex if info has been registered */
1236                 mutex_lock(&info->lock);
1237
1238         edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
1239         if (!edid) {
1240                 result = -ENOMEM;
1241                 goto error;
1242         }
1243
1244         fb_destroy_modelist(&info->modelist);
1245         memset(&info->monspecs, 0, sizeof(info->monspecs));
1246
1247         /*
1248          * Try to (re)read EDID from hardware first
1249          * EDID data may return, but not parse as valid
1250          * Try again a few times, in case of e.g. analog cable noise
1251          */
1252         while (tries--) {
1253
1254                 i = dlfb_get_edid(dev, edid, EDID_LENGTH);
1255
1256                 if (i >= EDID_LENGTH)
1257                         fb_edid_to_monspecs(edid, &info->monspecs);
1258
1259                 if (info->monspecs.modedb_len > 0) {
1260                         dev->edid = edid;
1261                         dev->edid_size = i;
1262                         break;
1263                 }
1264         }
1265
1266         /* If that fails, use a previously returned EDID if available */
1267         if (info->monspecs.modedb_len == 0) {
1268
1269                 pr_err("Unable to get valid EDID from device/display\n");
1270
1271                 if (dev->edid) {
1272                         fb_edid_to_monspecs(dev->edid, &info->monspecs);
1273                         if (info->monspecs.modedb_len > 0)
1274                                 pr_err("Using previously queried EDID\n");
1275                 }
1276         }
1277
1278         /* If that fails, use the default EDID we were handed */
1279         if (info->monspecs.modedb_len == 0) {
1280                 if (default_edid_size >= EDID_LENGTH) {
1281                         fb_edid_to_monspecs(default_edid, &info->monspecs);
1282                         if (info->monspecs.modedb_len > 0) {
1283                                 memcpy(edid, default_edid, default_edid_size);
1284                                 dev->edid = edid;
1285                                 dev->edid_size = default_edid_size;
1286                                 pr_err("Using default/backup EDID\n");
1287                         }
1288                 }
1289         }
1290
1291         /* If we've got modes, let's pick a best default mode */
1292         if (info->monspecs.modedb_len > 0) {
1293
1294                 for (i = 0; i < info->monspecs.modedb_len; i++) {
1295                         if (dlfb_is_valid_mode(&info->monspecs.modedb[i], info))
1296                                 fb_add_videomode(&info->monspecs.modedb[i],
1297                                         &info->modelist);
1298                         else {
1299                                 if (i == 0)
1300                                         /* if we've removed top/best mode */
1301                                         info->monspecs.misc
1302                                                 &= ~FB_MISC_1ST_DETAIL;
1303                         }
1304                 }
1305
1306                 default_vmode = fb_find_best_display(&info->monspecs,
1307                                                      &info->modelist);
1308         }
1309
1310         /* If everything else has failed, fall back to safe default mode */
1311         if (default_vmode == NULL) {
1312
1313                 struct fb_videomode fb_vmode = {0};
1314
1315                 /*
1316                  * Add the standard VESA modes to our modelist
1317                  * Since we don't have EDID, there may be modes that
1318                  * overspec monitor and/or are incorrect aspect ratio, etc.
1319                  * But at least the user has a chance to choose
1320                  */
1321                 for (i = 0; i < VESA_MODEDB_SIZE; i++) {
1322                         if (dlfb_is_valid_mode((struct fb_videomode *)
1323                                                 &vesa_modes[i], info))
1324                                 fb_add_videomode(&vesa_modes[i],
1325                                                  &info->modelist);
1326                 }
1327
1328                 /*
1329                  * default to resolution safe for projectors
1330                  * (since they are most common case without EDID)
1331                  */
1332                 fb_vmode.xres = 800;
1333                 fb_vmode.yres = 600;
1334                 fb_vmode.refresh = 60;
1335                 default_vmode = fb_find_nearest_mode(&fb_vmode,
1336                                                      &info->modelist);
1337         }
1338
1339         /* If we have good mode and no active clients*/
1340         if ((default_vmode != NULL) && (dev->fb_count == 0)) {
1341
1342                 fb_videomode_to_var(&info->var, default_vmode);
1343                 dlfb_var_color_format(&info->var);
1344
1345                 /*
1346                  * with mode size info, we can now alloc our framebuffer.
1347                  */
1348                 memcpy(&info->fix, &dlfb_fix, sizeof(dlfb_fix));
1349                 info->fix.line_length = info->var.xres *
1350                         (info->var.bits_per_pixel / 8);
1351
1352                 result = dlfb_realloc_framebuffer(dev, info);
1353
1354         } else
1355                 result = -EINVAL;
1356
1357 error:
1358         if (edid && (dev->edid != edid))
1359                 kfree(edid);
1360
1361         if (info->dev)
1362                 mutex_unlock(&info->lock);
1363
1364         return result;
1365 }
1366
1367 static ssize_t metrics_bytes_rendered_show(struct device *fbdev,
1368                                    struct device_attribute *a, char *buf) {
1369         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1370         struct dlfb_data *dev = fb_info->par;
1371         return snprintf(buf, PAGE_SIZE, "%u\n",
1372                         atomic_read(&dev->bytes_rendered));
1373 }
1374
1375 static ssize_t metrics_bytes_identical_show(struct device *fbdev,
1376                                    struct device_attribute *a, char *buf) {
1377         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1378         struct dlfb_data *dev = fb_info->par;
1379         return snprintf(buf, PAGE_SIZE, "%u\n",
1380                         atomic_read(&dev->bytes_identical));
1381 }
1382
1383 static ssize_t metrics_bytes_sent_show(struct device *fbdev,
1384                                    struct device_attribute *a, char *buf) {
1385         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1386         struct dlfb_data *dev = fb_info->par;
1387         return snprintf(buf, PAGE_SIZE, "%u\n",
1388                         atomic_read(&dev->bytes_sent));
1389 }
1390
1391 static ssize_t metrics_cpu_kcycles_used_show(struct device *fbdev,
1392                                    struct device_attribute *a, char *buf) {
1393         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1394         struct dlfb_data *dev = fb_info->par;
1395         return snprintf(buf, PAGE_SIZE, "%u\n",
1396                         atomic_read(&dev->cpu_kcycles_used));
1397 }
1398
1399 static ssize_t edid_show(
1400                         struct file *filp,
1401                         struct kobject *kobj, struct bin_attribute *a,
1402                          char *buf, loff_t off, size_t count) {
1403         struct device *fbdev = container_of(kobj, struct device, kobj);
1404         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1405         struct dlfb_data *dev = fb_info->par;
1406
1407         if (dev->edid == NULL)
1408                 return 0;
1409
1410         if ((off >= dev->edid_size) || (count > dev->edid_size))
1411                 return 0;
1412
1413         if (off + count > dev->edid_size)
1414                 count = dev->edid_size - off;
1415
1416         pr_info("sysfs edid copy %p to %p, %d bytes\n",
1417                 dev->edid, buf, (int) count);
1418
1419         memcpy(buf, dev->edid, count);
1420
1421         return count;
1422 }
1423
1424 static ssize_t edid_store(
1425                         struct file *filp,
1426                         struct kobject *kobj, struct bin_attribute *a,
1427                         char *src, loff_t src_off, size_t src_size) {
1428         struct device *fbdev = container_of(kobj, struct device, kobj);
1429         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1430         struct dlfb_data *dev = fb_info->par;
1431
1432         /* We only support write of entire EDID at once, no offset*/
1433         if ((src_size != EDID_LENGTH) || (src_off != 0))
1434                 return 0;
1435
1436         dlfb_setup_modes(dev, fb_info, src, src_size);
1437
1438         if (dev->edid && (memcmp(src, dev->edid, src_size) == 0)) {
1439                 pr_info("sysfs written EDID is new default\n");
1440                 dlfb_ops_set_par(fb_info);
1441                 return src_size;
1442         } else
1443                 return 0;
1444 }
1445
1446 static ssize_t metrics_reset_store(struct device *fbdev,
1447                            struct device_attribute *attr,
1448                            const char *buf, size_t count)
1449 {
1450         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1451         struct dlfb_data *dev = fb_info->par;
1452
1453         atomic_set(&dev->bytes_rendered, 0);
1454         atomic_set(&dev->bytes_identical, 0);
1455         atomic_set(&dev->bytes_sent, 0);
1456         atomic_set(&dev->cpu_kcycles_used, 0);
1457
1458         return count;
1459 }
1460
1461 static struct bin_attribute edid_attr = {
1462         .attr.name = "edid",
1463         .attr.mode = 0666,
1464         .size = EDID_LENGTH,
1465         .read = edid_show,
1466         .write = edid_store
1467 };
1468
1469 static struct device_attribute fb_device_attrs[] = {
1470         __ATTR_RO(metrics_bytes_rendered),
1471         __ATTR_RO(metrics_bytes_identical),
1472         __ATTR_RO(metrics_bytes_sent),
1473         __ATTR_RO(metrics_cpu_kcycles_used),
1474         __ATTR(metrics_reset, S_IWUSR, NULL, metrics_reset_store),
1475 };
1476
1477 /*
1478  * This is necessary before we can communicate with the display controller.
1479  */
1480 static int dlfb_select_std_channel(struct dlfb_data *dev)
1481 {
1482         int ret;
1483         u8 set_def_chn[] = {       0x57, 0xCD, 0xDC, 0xA7,
1484                                 0x1C, 0x88, 0x5E, 0x15,
1485                                 0x60, 0xFE, 0xC6, 0x97,
1486                                 0x16, 0x3D, 0x47, 0xF2  };
1487
1488         ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1489                         NR_USB_REQUEST_CHANNEL,
1490                         (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
1491                         set_def_chn, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT);
1492         return ret;
1493 }
1494
1495 static int dlfb_parse_vendor_descriptor(struct dlfb_data *dev,
1496                                         struct usb_interface *interface)
1497 {
1498         char *desc;
1499         char *buf;
1500         char *desc_end;
1501
1502         int total_len = 0;
1503
1504         buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
1505         if (!buf)
1506                 return false;
1507         desc = buf;
1508
1509         total_len = usb_get_descriptor(interface_to_usbdev(interface),
1510                                         0x5f, /* vendor specific */
1511                                         0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
1512
1513         /* if not found, look in configuration descriptor */
1514         if (total_len < 0) {
1515                 if (0 == usb_get_extra_descriptor(interface->cur_altsetting,
1516                         0x5f, &desc))
1517                         total_len = (int) desc[0];
1518         }
1519
1520         if (total_len > 5) {
1521                 pr_info("vendor descriptor length:%x data:%02x %02x %02x %02x" \
1522                         "%02x %02x %02x %02x %02x %02x %02x\n",
1523                         total_len, desc[0],
1524                         desc[1], desc[2], desc[3], desc[4], desc[5], desc[6],
1525                         desc[7], desc[8], desc[9], desc[10]);
1526
1527                 if ((desc[0] != total_len) || /* descriptor length */
1528                     (desc[1] != 0x5f) ||   /* vendor descriptor type */
1529                     (desc[2] != 0x01) ||   /* version (2 bytes) */
1530                     (desc[3] != 0x00) ||
1531                     (desc[4] != total_len - 2)) /* length after type */
1532                         goto unrecognized;
1533
1534                 desc_end = desc + total_len;
1535                 desc += 5; /* the fixed header we've already parsed */
1536
1537                 while (desc < desc_end) {
1538                         u8 length;
1539                         u16 key;
1540
1541                         key = *((u16 *) desc);
1542                         desc += sizeof(u16);
1543                         length = *desc;
1544                         desc++;
1545
1546                         switch (key) {
1547                         case 0x0200: { /* max_area */
1548                                 u32 max_area;
1549                                 max_area = le32_to_cpu(*((u32 *)desc));
1550                                 pr_warn("DL chip limited to %d pixel modes\n",
1551                                         max_area);
1552                                 dev->sku_pixel_limit = max_area;
1553                                 break;
1554                         }
1555                         default:
1556                                 break;
1557                         }
1558                         desc += length;
1559                 }
1560         } else {
1561                 pr_info("vendor descriptor not available (%d)\n", total_len);
1562         }
1563
1564         goto success;
1565
1566 unrecognized:
1567         /* allow udlfb to load for now even if firmware unrecognized */
1568         pr_err("Unrecognized vendor firmware descriptor\n");
1569
1570 success:
1571         kfree(buf);
1572         return true;
1573 }
1574 static int dlfb_usb_probe(struct usb_interface *interface,
1575                         const struct usb_device_id *id)
1576 {
1577         struct usb_device *usbdev;
1578         struct dlfb_data *dev = 0;
1579         struct fb_info *info = 0;
1580         int retval = -ENOMEM;
1581         int i;
1582
1583         /* usb initialization */
1584
1585         usbdev = interface_to_usbdev(interface);
1586
1587         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1588         if (dev == NULL) {
1589                 err("dlfb_usb_probe: failed alloc of dev struct\n");
1590                 goto error;
1591         }
1592
1593         /* we need to wait for both usb and fbdev to spin down on disconnect */
1594         kref_init(&dev->kref); /* matching kref_put in usb .disconnect fn */
1595         kref_get(&dev->kref); /* matching kref_put in free_framebuffer_work */
1596
1597         dev->udev = usbdev;
1598         dev->gdev = &usbdev->dev; /* our generic struct device * */
1599         usb_set_intfdata(interface, dev);
1600
1601         pr_info("%s %s - serial #%s\n",
1602                 usbdev->manufacturer, usbdev->product, usbdev->serial);
1603         pr_info("vid_%04x&pid_%04x&rev_%04x driver's dlfb_data struct at %p\n",
1604                 usbdev->descriptor.idVendor, usbdev->descriptor.idProduct,
1605                 usbdev->descriptor.bcdDevice, dev);
1606         pr_info("console enable=%d\n", console);
1607         pr_info("fb_defio enable=%d\n", fb_defio);
1608         pr_info("shadow enable=%d\n", shadow);
1609
1610         dev->sku_pixel_limit = 2048 * 1152; /* default to maximum */
1611
1612         if (!dlfb_parse_vendor_descriptor(dev, interface)) {
1613                 pr_err("firmware not recognized. Assume incompatible device\n");
1614                 goto error;
1615         }
1616
1617         if (!dlfb_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
1618                 retval = -ENOMEM;
1619                 pr_err("dlfb_alloc_urb_list failed\n");
1620                 goto error;
1621         }
1622
1623         /* We don't register a new USB class. Our client interface is fbdev */
1624
1625         /* allocates framebuffer driver structure, not framebuffer memory */
1626         info = framebuffer_alloc(0, &interface->dev);
1627         if (!info) {
1628                 retval = -ENOMEM;
1629                 pr_err("framebuffer_alloc failed\n");
1630                 goto error;
1631         }
1632
1633         dev->info = info;
1634         info->par = dev;
1635         info->pseudo_palette = dev->pseudo_palette;
1636         info->fbops = &dlfb_ops;
1637
1638         retval = fb_alloc_cmap(&info->cmap, 256, 0);
1639         if (retval < 0) {
1640                 pr_err("fb_alloc_cmap failed %x\n", retval);
1641                 goto error;
1642         }
1643
1644         INIT_DELAYED_WORK(&dev->free_framebuffer_work,
1645                           dlfb_free_framebuffer_work);
1646
1647         INIT_LIST_HEAD(&info->modelist);
1648
1649         retval = dlfb_setup_modes(dev, info, NULL, 0);
1650         if (retval != 0) {
1651                 pr_err("unable to find common mode for display and adapter\n");
1652                 goto error;
1653         }
1654
1655         /* ready to begin using device */
1656
1657         atomic_set(&dev->usb_active, 1);
1658         dlfb_select_std_channel(dev);
1659
1660         dlfb_ops_check_var(&info->var, info);
1661         dlfb_ops_set_par(info);
1662
1663         retval = register_framebuffer(info);
1664         if (retval < 0) {
1665                 pr_err("register_framebuffer failed %d\n", retval);
1666                 goto error;
1667         }
1668
1669         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) {
1670                 retval = device_create_file(info->dev, &fb_device_attrs[i]);
1671                 if (retval) {
1672                         pr_err("device_create_file failed %d\n", retval);
1673                         goto err_del_attrs;
1674                 }
1675         }
1676
1677         retval = device_create_bin_file(info->dev, &edid_attr);
1678         if (retval) {
1679                 pr_err("device_create_bin_file failed %d\n", retval);
1680                 goto err_del_attrs;
1681         }
1682
1683         pr_info("DisplayLink USB device /dev/fb%d attached. %dx%d resolution."
1684                         " Using %dK framebuffer memory\n", info->node,
1685                         info->var.xres, info->var.yres,
1686                         ((dev->backing_buffer) ?
1687                         info->fix.smem_len * 2 : info->fix.smem_len) >> 10);
1688         return 0;
1689
1690 err_del_attrs:
1691         for (i -= 1; i >= 0; i--)
1692                 device_remove_file(info->dev, &fb_device_attrs[i]);
1693
1694 error:
1695         if (dev) {
1696
1697                 if (info) {
1698                         if (info->cmap.len != 0)
1699                                 fb_dealloc_cmap(&info->cmap);
1700                         if (info->monspecs.modedb)
1701                                 fb_destroy_modedb(info->monspecs.modedb);
1702                         if (info->screen_base)
1703                                 vfree(info->screen_base);
1704
1705                         fb_destroy_modelist(&info->modelist);
1706
1707                         framebuffer_release(info);
1708                 }
1709
1710                 if (dev->backing_buffer)
1711                         vfree(dev->backing_buffer);
1712
1713                 kref_put(&dev->kref, dlfb_free); /* ref for framebuffer */
1714                 kref_put(&dev->kref, dlfb_free); /* last ref from kref_init */
1715
1716                 /* dev has been deallocated. Do not dereference */
1717         }
1718
1719         return retval;
1720 }
1721
1722 static void dlfb_usb_disconnect(struct usb_interface *interface)
1723 {
1724         struct dlfb_data *dev;
1725         struct fb_info *info;
1726         int i;
1727
1728         dev = usb_get_intfdata(interface);
1729         info = dev->info;
1730
1731         pr_info("USB disconnect starting\n");
1732
1733         /* we virtualize until all fb clients release. Then we free */
1734         dev->virtualized = true;
1735
1736         /* When non-active we'll update virtual framebuffer, but no new urbs */
1737         atomic_set(&dev->usb_active, 0);
1738
1739         /* remove udlfb's sysfs interfaces */
1740         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1741                 device_remove_file(info->dev, &fb_device_attrs[i]);
1742         device_remove_bin_file(info->dev, &edid_attr);
1743         unlink_framebuffer(info);
1744         usb_set_intfdata(interface, NULL);
1745
1746         /* if clients still have us open, will be freed on last close */
1747         if (dev->fb_count == 0)
1748                 schedule_delayed_work(&dev->free_framebuffer_work, 0);
1749
1750         /* release reference taken by kref_init in probe() */
1751         kref_put(&dev->kref, dlfb_free);
1752
1753         /* consider dlfb_data freed */
1754
1755         return;
1756 }
1757
1758 static struct usb_driver dlfb_driver = {
1759         .name = "udlfb",
1760         .probe = dlfb_usb_probe,
1761         .disconnect = dlfb_usb_disconnect,
1762         .id_table = id_table,
1763 };
1764
1765 module_usb_driver(dlfb_driver);
1766
1767 static void dlfb_urb_completion(struct urb *urb)
1768 {
1769         struct urb_node *unode = urb->context;
1770         struct dlfb_data *dev = unode->dev;
1771         unsigned long flags;
1772
1773         /* sync/async unlink faults aren't errors */
1774         if (urb->status) {
1775                 if (!(urb->status == -ENOENT ||
1776                     urb->status == -ECONNRESET ||
1777                     urb->status == -ESHUTDOWN)) {
1778                         pr_err("%s - nonzero write bulk status received: %d\n",
1779                                 __func__, urb->status);
1780                         atomic_set(&dev->lost_pixels, 1);
1781                 }
1782         }
1783
1784         urb->transfer_buffer_length = dev->urbs.size; /* reset to actual */
1785
1786         spin_lock_irqsave(&dev->urbs.lock, flags);
1787         list_add_tail(&unode->entry, &dev->urbs.list);
1788         dev->urbs.available++;
1789         spin_unlock_irqrestore(&dev->urbs.lock, flags);
1790
1791         /*
1792          * When using fb_defio, we deadlock if up() is called
1793          * while another is waiting. So queue to another process.
1794          */
1795         if (fb_defio)
1796                 schedule_delayed_work(&unode->release_urb_work, 0);
1797         else
1798                 up(&dev->urbs.limit_sem);
1799 }
1800
1801 static void dlfb_free_urb_list(struct dlfb_data *dev)
1802 {
1803         int count = dev->urbs.count;
1804         struct list_head *node;
1805         struct urb_node *unode;
1806         struct urb *urb;
1807         int ret;
1808         unsigned long flags;
1809
1810         pr_notice("Waiting for completes and freeing all render urbs\n");
1811
1812         /* keep waiting and freeing, until we've got 'em all */
1813         while (count--) {
1814
1815                 /* Getting interrupted means a leak, but ok at shutdown*/
1816                 ret = down_interruptible(&dev->urbs.limit_sem);
1817                 if (ret)
1818                         break;
1819
1820                 spin_lock_irqsave(&dev->urbs.lock, flags);
1821
1822                 node = dev->urbs.list.next; /* have reserved one with sem */
1823                 list_del_init(node);
1824
1825                 spin_unlock_irqrestore(&dev->urbs.lock, flags);
1826
1827                 unode = list_entry(node, struct urb_node, entry);
1828                 urb = unode->urb;
1829
1830                 /* Free each separately allocated piece */
1831                 usb_free_coherent(urb->dev, dev->urbs.size,
1832                                   urb->transfer_buffer, urb->transfer_dma);
1833                 usb_free_urb(urb);
1834                 kfree(node);
1835         }
1836
1837 }
1838
1839 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size)
1840 {
1841         int i = 0;
1842         struct urb *urb;
1843         struct urb_node *unode;
1844         char *buf;
1845
1846         spin_lock_init(&dev->urbs.lock);
1847
1848         dev->urbs.size = size;
1849         INIT_LIST_HEAD(&dev->urbs.list);
1850
1851         while (i < count) {
1852                 unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
1853                 if (!unode)
1854                         break;
1855                 unode->dev = dev;
1856
1857                 INIT_DELAYED_WORK(&unode->release_urb_work,
1858                           dlfb_release_urb_work);
1859
1860                 urb = usb_alloc_urb(0, GFP_KERNEL);
1861                 if (!urb) {
1862                         kfree(unode);
1863                         break;
1864                 }
1865                 unode->urb = urb;
1866
1867                 buf = usb_alloc_coherent(dev->udev, MAX_TRANSFER, GFP_KERNEL,
1868                                          &urb->transfer_dma);
1869                 if (!buf) {
1870                         kfree(unode);
1871                         usb_free_urb(urb);
1872                         break;
1873                 }
1874
1875                 /* urb->transfer_buffer_length set to actual before submit */
1876                 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
1877                         buf, size, dlfb_urb_completion, unode);
1878                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1879
1880                 list_add_tail(&unode->entry, &dev->urbs.list);
1881
1882                 i++;
1883         }
1884
1885         sema_init(&dev->urbs.limit_sem, i);
1886         dev->urbs.count = i;
1887         dev->urbs.available = i;
1888
1889         pr_notice("allocated %d %d byte urbs\n", i, (int) size);
1890
1891         return i;
1892 }
1893
1894 static struct urb *dlfb_get_urb(struct dlfb_data *dev)
1895 {
1896         int ret = 0;
1897         struct list_head *entry;
1898         struct urb_node *unode;
1899         struct urb *urb = NULL;
1900         unsigned long flags;
1901
1902         /* Wait for an in-flight buffer to complete and get re-queued */
1903         ret = down_timeout(&dev->urbs.limit_sem, GET_URB_TIMEOUT);
1904         if (ret) {
1905                 atomic_set(&dev->lost_pixels, 1);
1906                 pr_warn("wait for urb interrupted: %x available: %d\n",
1907                        ret, dev->urbs.available);
1908                 goto error;
1909         }
1910
1911         spin_lock_irqsave(&dev->urbs.lock, flags);
1912
1913         BUG_ON(list_empty(&dev->urbs.list)); /* reserved one with limit_sem */
1914         entry = dev->urbs.list.next;
1915         list_del_init(entry);
1916         dev->urbs.available--;
1917
1918         spin_unlock_irqrestore(&dev->urbs.lock, flags);
1919
1920         unode = list_entry(entry, struct urb_node, entry);
1921         urb = unode->urb;
1922
1923 error:
1924         return urb;
1925 }
1926
1927 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb *urb, size_t len)
1928 {
1929         int ret;
1930
1931         BUG_ON(len > dev->urbs.size);
1932
1933         urb->transfer_buffer_length = len; /* set to actual payload len */
1934         ret = usb_submit_urb(urb, GFP_KERNEL);
1935         if (ret) {
1936                 dlfb_urb_completion(urb); /* because no one else will */
1937                 atomic_set(&dev->lost_pixels, 1);
1938                 pr_err("usb_submit_urb error %x\n", ret);
1939         }
1940         return ret;
1941 }
1942
1943 module_param(console, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1944 MODULE_PARM_DESC(console, "Allow fbcon to open framebuffer");
1945
1946 module_param(fb_defio, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1947 MODULE_PARM_DESC(fb_defio, "Page fault detection of mmap writes");
1948
1949 module_param(shadow, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1950 MODULE_PARM_DESC(shadow, "Shadow vid mem. Disable to save mem but lose perf");
1951
1952 MODULE_AUTHOR("Roberto De Ioris <roberto@unbit.it>, "
1953               "Jaya Kumar <jayakumar.lkml@gmail.com>, "
1954               "Bernie Thompson <bernie@plugable.com>");
1955 MODULE_DESCRIPTION("DisplayLink kernel framebuffer driver");
1956 MODULE_LICENSE("GPL");
1957