udl-kms: avoid prefetch
authorMikulas Patocka <mpatocka@redhat.com>
Sun, 3 Jun 2018 14:41:01 +0000 (16:41 +0200)
committerDave Airlie <airlied@redhat.com>
Mon, 30 Jul 2018 22:11:12 +0000 (08:11 +1000)
Modern processors can detect linear memory accesses and prefetch data
automatically, so there's no need to use prefetch.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
drivers/gpu/drm/udl/udl_transfer.c

index f3331d33547a1708fc7be2ee4eaeda676da3ff13..ce87661e544f7a4cc37bb6a03d89104d3ea97e72 100644 (file)
@@ -13,7 +13,6 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/fb.h>
-#include <linux/prefetch.h>
 #include <asm/unaligned.h>
 
 #include <drm/drmP.h>
@@ -51,9 +50,6 @@ static int udl_trim_hline(const u8 *bback, const u8 **bfront, int *width_bytes)
        int start = width;
        int end = width;
 
-       prefetch((void *) front);
-       prefetch((void *) back);
-
        for (j = 0; j < width; j++) {
                if (back[j] != front[j]) {
                        start = j;
@@ -140,8 +136,6 @@ static void udl_compress_hline16(
                const u8 *cmd_pixel_start, *cmd_pixel_end = NULL;
                uint16_t pixel_val16;
 
-               prefetchw((void *) cmd); /* pull in one cache line at least */
-
                *cmd++ = 0xaf;
                *cmd++ = 0x6b;
                *cmd++ = (uint8_t) ((dev_addr >> 16) & 0xFF);
@@ -158,7 +152,6 @@ static void udl_compress_hline16(
                                        (unsigned long)(pixel_end - pixel) >> log_bpp,
                                        (unsigned long)(cmd_buffer_end - 1 - cmd) / 2) << log_bpp);
 
-               prefetch_range((void *) pixel, cmd_pixel_end - pixel);
                pixel_val16 = get_pixel_val16(pixel, log_bpp);
 
                while (pixel < cmd_pixel_end) {