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51fd371b RC |
1 | /* |
2 | * Copyright (C) 2014 Red Hat | |
3 | * Author: Rob Clark <robdclark@gmail.com> | |
4 | * | |
5 | * Permission is hereby granted, free of charge, to any person obtaining a | |
6 | * copy of this software and associated documentation files (the "Software"), | |
7 | * to deal in the Software without restriction, including without limitation | |
8 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, | |
9 | * and/or sell copies of the Software, and to permit persons to whom the | |
10 | * Software is furnished to do so, subject to the following conditions: | |
11 | * | |
12 | * The above copyright notice and this permission notice shall be included in | |
13 | * all copies or substantial portions of the Software. | |
14 | * | |
15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
16 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
17 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
18 | * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR | |
19 | * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, | |
20 | * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR | |
21 | * OTHER DEALINGS IN THE SOFTWARE. | |
22 | */ | |
23 | ||
b962a120 | 24 | #include <drm/drm_atomic.h> |
51fd371b | 25 | #include <drm/drm_crtc.h> |
0500c04e | 26 | #include <drm/drm_device.h> |
51fd371b | 27 | #include <drm/drm_modeset_lock.h> |
cd06ab2f | 28 | #include <drm/drm_print.h> |
51fd371b RC |
29 | |
30 | /** | |
31 | * DOC: kms locking | |
32 | * | |
33 | * As KMS moves toward more fine grained locking, and atomic ioctl where | |
34 | * userspace can indirectly control locking order, it becomes necessary | |
0645de5a | 35 | * to use &ww_mutex and acquire-contexts to avoid deadlocks. But because |
51fd371b RC |
36 | * the locking is more distributed around the driver code, we want a bit |
37 | * of extra utility/tracking out of our acquire-ctx. This is provided | |
d574528a | 38 | * by &struct drm_modeset_lock and &struct drm_modeset_acquire_ctx. |
51fd371b | 39 | * |
387b1468 | 40 | * For basic principles of &ww_mutex, see: Documentation/locking/ww-mutex-design.rst |
51fd371b | 41 | * |
da5335b8 | 42 | * The basic usage pattern is to:: |
51fd371b | 43 | * |
6f8bcc74 | 44 | * drm_modeset_acquire_init(ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE) |
f03d8ede | 45 | * retry: |
51fd371b | 46 | * foreach (lock in random_ordered_set_of_locks) { |
6f8bcc74 | 47 | * ret = drm_modeset_lock(lock, ctx) |
f03d8ede | 48 | * if (ret == -EDEADLK) { |
6f8bcc74 ML |
49 | * ret = drm_modeset_backoff(ctx); |
50 | * if (!ret) | |
51 | * goto retry; | |
f03d8ede | 52 | * } |
6f8bcc74 ML |
53 | * if (ret) |
54 | * goto out; | |
51fd371b | 55 | * } |
51fd371b | 56 | * ... do stuff ... |
6f8bcc74 ML |
57 | * out: |
58 | * drm_modeset_drop_locks(ctx); | |
59 | * drm_modeset_acquire_fini(ctx); | |
0645de5a | 60 | * |
b7ea04d2 SP |
61 | * For convenience this control flow is implemented in |
62 | * DRM_MODESET_LOCK_ALL_BEGIN() and DRM_MODESET_LOCK_ALL_END() for the case | |
63 | * where all modeset locks need to be taken through drm_modeset_lock_all_ctx(). | |
64 | * | |
fc2157b6 LD |
65 | * If all that is needed is a single modeset lock, then the &struct |
66 | * drm_modeset_acquire_ctx is not needed and the locking can be simplified | |
6f8bcc74 ML |
67 | * by passing a NULL instead of ctx in the drm_modeset_lock() call or |
68 | * calling drm_modeset_lock_single_interruptible(). To unlock afterwards | |
69 | * call drm_modeset_unlock(). | |
fc2157b6 LD |
70 | * |
71 | * On top of these per-object locks using &ww_mutex there's also an overall | |
d574528a | 72 | * &drm_mode_config.mutex, for protecting everything else. Mostly this means |
b07c4254 | 73 | * probe state of connectors, and preventing hotplug add/removal of connectors. |
0645de5a | 74 | * |
b07c4254 DV |
75 | * Finally there's a bunch of dedicated locks to protect drm core internal |
76 | * lists and lookup data structures. | |
51fd371b RC |
77 | */ |
78 | ||
35cf0350 RC |
79 | static DEFINE_WW_CLASS(crtc_ww_class); |
80 | ||
cd06ab2f | 81 | #if IS_ENABLED(CONFIG_DRM_DEBUG_MODESET_LOCK) |
bcae3af2 | 82 | static noinline depot_stack_handle_t __drm_stack_depot_save(void) |
cd06ab2f JN |
83 | { |
84 | unsigned long entries[8]; | |
85 | unsigned int n; | |
86 | ||
87 | n = stack_trace_save(entries, ARRAY_SIZE(entries), 1); | |
88 | ||
89 | return stack_depot_save(entries, n, GFP_NOWAIT | __GFP_NOWARN); | |
90 | } | |
91 | ||
bcae3af2 | 92 | static void __drm_stack_depot_print(depot_stack_handle_t stack_depot) |
cd06ab2f JN |
93 | { |
94 | struct drm_printer p = drm_debug_printer("drm_modeset_lock"); | |
95 | unsigned long *entries; | |
96 | unsigned int nr_entries; | |
97 | char *buf; | |
98 | ||
99 | buf = kmalloc(PAGE_SIZE, GFP_NOWAIT | __GFP_NOWARN); | |
100 | if (!buf) | |
101 | return; | |
102 | ||
103 | nr_entries = stack_depot_fetch(stack_depot, &entries); | |
104 | stack_trace_snprint(buf, PAGE_SIZE, entries, nr_entries, 2); | |
105 | ||
106 | drm_printf(&p, "attempting to lock a contended lock without backoff:\n%s", buf); | |
107 | ||
108 | kfree(buf); | |
109 | } | |
2dba5eb1 VB |
110 | |
111 | static void __drm_stack_depot_init(void) | |
112 | { | |
113 | stack_depot_init(); | |
114 | } | |
cd06ab2f | 115 | #else /* CONFIG_DRM_DEBUG_MODESET_LOCK */ |
bcae3af2 | 116 | static depot_stack_handle_t __drm_stack_depot_save(void) |
cd06ab2f JN |
117 | { |
118 | return 0; | |
119 | } | |
bcae3af2 | 120 | static void __drm_stack_depot_print(depot_stack_handle_t stack_depot) |
cd06ab2f JN |
121 | { |
122 | } | |
2dba5eb1 VB |
123 | static void __drm_stack_depot_init(void) |
124 | { | |
125 | } | |
cd06ab2f JN |
126 | #endif /* CONFIG_DRM_DEBUG_MODESET_LOCK */ |
127 | ||
a6a8bb84 | 128 | /** |
bf9e37ba | 129 | * drm_modeset_lock_all - take all modeset locks |
06eaae46 | 130 | * @dev: DRM device |
cb597bb3 | 131 | * |
bf9e37ba | 132 | * This function takes all modeset locks, suitable where a more fine-grained |
06eaae46 TR |
133 | * scheme isn't (yet) implemented. Locks must be dropped by calling the |
134 | * drm_modeset_unlock_all() function. | |
135 | * | |
136 | * This function is deprecated. It allocates a lock acquisition context and | |
d574528a | 137 | * stores it in &drm_device.mode_config. This facilitate conversion of |
06eaae46 TR |
138 | * existing code because it removes the need to manually deal with the |
139 | * acquisition context, but it is also brittle because the context is global | |
140 | * and care must be taken not to nest calls. New code should use the | |
141 | * drm_modeset_lock_all_ctx() function and pass in the context explicitly. | |
a6a8bb84 | 142 | */ |
bf9e37ba | 143 | void drm_modeset_lock_all(struct drm_device *dev) |
a6a8bb84 DV |
144 | { |
145 | struct drm_mode_config *config = &dev->mode_config; | |
146 | struct drm_modeset_acquire_ctx *ctx; | |
147 | int ret; | |
148 | ||
d18d1a5a | 149 | ctx = kzalloc(sizeof(*ctx), GFP_KERNEL | __GFP_NOFAIL); |
bf9e37ba DV |
150 | if (WARN_ON(!ctx)) |
151 | return; | |
152 | ||
153 | mutex_lock(&config->mutex); | |
a6a8bb84 DV |
154 | |
155 | drm_modeset_acquire_init(ctx, 0); | |
156 | ||
157 | retry: | |
06eaae46 TR |
158 | ret = drm_modeset_lock_all_ctx(dev, ctx); |
159 | if (ret < 0) { | |
160 | if (ret == -EDEADLK) { | |
161 | drm_modeset_backoff(ctx); | |
162 | goto retry; | |
163 | } | |
164 | ||
165 | drm_modeset_acquire_fini(ctx); | |
166 | kfree(ctx); | |
167 | return; | |
168 | } | |
5fcdc9d9 | 169 | ww_acquire_done(&ctx->ww_ctx); |
a6a8bb84 DV |
170 | |
171 | WARN_ON(config->acquire_ctx); | |
172 | ||
06eaae46 TR |
173 | /* |
174 | * We hold the locks now, so it is safe to stash the acquisition | |
175 | * context for drm_modeset_unlock_all(). | |
a6a8bb84 DV |
176 | */ |
177 | config->acquire_ctx = ctx; | |
178 | ||
179 | drm_warn_on_modeset_not_all_locked(dev); | |
a6a8bb84 DV |
180 | } |
181 | EXPORT_SYMBOL(drm_modeset_lock_all); | |
182 | ||
183 | /** | |
184 | * drm_modeset_unlock_all - drop all modeset locks | |
06eaae46 | 185 | * @dev: DRM device |
a6a8bb84 | 186 | * |
06eaae46 TR |
187 | * This function drops all modeset locks taken by a previous call to the |
188 | * drm_modeset_lock_all() function. | |
189 | * | |
190 | * This function is deprecated. It uses the lock acquisition context stored | |
d574528a | 191 | * in &drm_device.mode_config. This facilitates conversion of existing |
06eaae46 TR |
192 | * code because it removes the need to manually deal with the acquisition |
193 | * context, but it is also brittle because the context is global and care must | |
194 | * be taken not to nest calls. New code should pass the acquisition context | |
195 | * directly to the drm_modeset_drop_locks() function. | |
a6a8bb84 DV |
196 | */ |
197 | void drm_modeset_unlock_all(struct drm_device *dev) | |
198 | { | |
199 | struct drm_mode_config *config = &dev->mode_config; | |
200 | struct drm_modeset_acquire_ctx *ctx = config->acquire_ctx; | |
201 | ||
202 | if (WARN_ON(!ctx)) | |
203 | return; | |
204 | ||
205 | config->acquire_ctx = NULL; | |
206 | drm_modeset_drop_locks(ctx); | |
207 | drm_modeset_acquire_fini(ctx); | |
208 | ||
209 | kfree(ctx); | |
210 | ||
211 | mutex_unlock(&dev->mode_config.mutex); | |
212 | } | |
213 | EXPORT_SYMBOL(drm_modeset_unlock_all); | |
214 | ||
215 | /** | |
216 | * drm_warn_on_modeset_not_all_locked - check that all modeset locks are locked | |
217 | * @dev: device | |
218 | * | |
219 | * Useful as a debug assert. | |
220 | */ | |
221 | void drm_warn_on_modeset_not_all_locked(struct drm_device *dev) | |
222 | { | |
223 | struct drm_crtc *crtc; | |
224 | ||
225 | /* Locking is currently fubar in the panic handler. */ | |
226 | if (oops_in_progress) | |
227 | return; | |
228 | ||
e4f62546 | 229 | drm_for_each_crtc(crtc, dev) |
a6a8bb84 DV |
230 | WARN_ON(!drm_modeset_is_locked(&crtc->mutex)); |
231 | ||
232 | WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex)); | |
233 | WARN_ON(!mutex_is_locked(&dev->mode_config.mutex)); | |
234 | } | |
235 | EXPORT_SYMBOL(drm_warn_on_modeset_not_all_locked); | |
236 | ||
51fd371b RC |
237 | /** |
238 | * drm_modeset_acquire_init - initialize acquire context | |
239 | * @ctx: the acquire context | |
6f8bcc74 ML |
240 | * @flags: 0 or %DRM_MODESET_ACQUIRE_INTERRUPTIBLE |
241 | * | |
242 | * When passing %DRM_MODESET_ACQUIRE_INTERRUPTIBLE to @flags, | |
243 | * all calls to drm_modeset_lock() will perform an interruptible | |
244 | * wait. | |
51fd371b RC |
245 | */ |
246 | void drm_modeset_acquire_init(struct drm_modeset_acquire_ctx *ctx, | |
247 | uint32_t flags) | |
248 | { | |
fb54918a | 249 | memset(ctx, 0, sizeof(*ctx)); |
51fd371b RC |
250 | ww_acquire_init(&ctx->ww_ctx, &crtc_ww_class); |
251 | INIT_LIST_HEAD(&ctx->locked); | |
6f8bcc74 ML |
252 | |
253 | if (flags & DRM_MODESET_ACQUIRE_INTERRUPTIBLE) | |
254 | ctx->interruptible = true; | |
51fd371b RC |
255 | } |
256 | EXPORT_SYMBOL(drm_modeset_acquire_init); | |
257 | ||
258 | /** | |
259 | * drm_modeset_acquire_fini - cleanup acquire context | |
260 | * @ctx: the acquire context | |
261 | */ | |
262 | void drm_modeset_acquire_fini(struct drm_modeset_acquire_ctx *ctx) | |
263 | { | |
264 | ww_acquire_fini(&ctx->ww_ctx); | |
265 | } | |
266 | EXPORT_SYMBOL(drm_modeset_acquire_fini); | |
267 | ||
268 | /** | |
269 | * drm_modeset_drop_locks - drop all locks | |
270 | * @ctx: the acquire context | |
271 | * | |
272 | * Drop all locks currently held against this acquire context. | |
273 | */ | |
274 | void drm_modeset_drop_locks(struct drm_modeset_acquire_ctx *ctx) | |
275 | { | |
cd06ab2f | 276 | if (WARN_ON(ctx->contended)) |
bcae3af2 | 277 | __drm_stack_depot_print(ctx->stack_depot); |
cd06ab2f | 278 | |
51fd371b RC |
279 | while (!list_empty(&ctx->locked)) { |
280 | struct drm_modeset_lock *lock; | |
281 | ||
282 | lock = list_first_entry(&ctx->locked, | |
283 | struct drm_modeset_lock, head); | |
284 | ||
285 | drm_modeset_unlock(lock); | |
286 | } | |
287 | } | |
288 | EXPORT_SYMBOL(drm_modeset_drop_locks); | |
289 | ||
290 | static inline int modeset_lock(struct drm_modeset_lock *lock, | |
291 | struct drm_modeset_acquire_ctx *ctx, | |
292 | bool interruptible, bool slow) | |
293 | { | |
294 | int ret; | |
295 | ||
cd06ab2f | 296 | if (WARN_ON(ctx->contended)) |
bcae3af2 | 297 | __drm_stack_depot_print(ctx->stack_depot); |
51fd371b | 298 | |
cb597bb3 | 299 | if (ctx->trylock_only) { |
825926d8 ML |
300 | lockdep_assert_held(&ctx->ww_ctx); |
301 | ||
12235da8 | 302 | if (!ww_mutex_trylock(&lock->mutex, NULL)) |
cb597bb3 DV |
303 | return -EBUSY; |
304 | else | |
305 | return 0; | |
306 | } else if (interruptible && slow) { | |
51fd371b RC |
307 | ret = ww_mutex_lock_slow_interruptible(&lock->mutex, &ctx->ww_ctx); |
308 | } else if (interruptible) { | |
309 | ret = ww_mutex_lock_interruptible(&lock->mutex, &ctx->ww_ctx); | |
310 | } else if (slow) { | |
311 | ww_mutex_lock_slow(&lock->mutex, &ctx->ww_ctx); | |
312 | ret = 0; | |
313 | } else { | |
314 | ret = ww_mutex_lock(&lock->mutex, &ctx->ww_ctx); | |
315 | } | |
316 | if (!ret) { | |
317 | WARN_ON(!list_empty(&lock->head)); | |
318 | list_add(&lock->head, &ctx->locked); | |
319 | } else if (ret == -EALREADY) { | |
320 | /* we already hold the lock.. this is fine. For atomic | |
321 | * we will need to be able to drm_modeset_lock() things | |
322 | * without having to keep track of what is already locked | |
323 | * or not. | |
324 | */ | |
325 | ret = 0; | |
326 | } else if (ret == -EDEADLK) { | |
327 | ctx->contended = lock; | |
bcae3af2 | 328 | ctx->stack_depot = __drm_stack_depot_save(); |
51fd371b RC |
329 | } |
330 | ||
331 | return ret; | |
332 | } | |
333 | ||
6f8bcc74 ML |
334 | /** |
335 | * drm_modeset_backoff - deadlock avoidance backoff | |
336 | * @ctx: the acquire context | |
337 | * | |
338 | * If deadlock is detected (ie. drm_modeset_lock() returns -EDEADLK), | |
339 | * you must call this function to drop all currently held locks and | |
340 | * block until the contended lock becomes available. | |
341 | * | |
342 | * This function returns 0 on success, or -ERESTARTSYS if this context | |
343 | * is initialized with %DRM_MODESET_ACQUIRE_INTERRUPTIBLE and the | |
344 | * wait has been interrupted. | |
345 | */ | |
346 | int drm_modeset_backoff(struct drm_modeset_acquire_ctx *ctx) | |
51fd371b RC |
347 | { |
348 | struct drm_modeset_lock *contended = ctx->contended; | |
349 | ||
350 | ctx->contended = NULL; | |
cd06ab2f | 351 | ctx->stack_depot = 0; |
51fd371b RC |
352 | |
353 | if (WARN_ON(!contended)) | |
354 | return 0; | |
355 | ||
356 | drm_modeset_drop_locks(ctx); | |
357 | ||
6f8bcc74 | 358 | return modeset_lock(contended, ctx, ctx->interruptible, true); |
51fd371b RC |
359 | } |
360 | EXPORT_SYMBOL(drm_modeset_backoff); | |
361 | ||
35cf0350 RC |
362 | /** |
363 | * drm_modeset_lock_init - initialize lock | |
364 | * @lock: lock to init | |
365 | */ | |
366 | void drm_modeset_lock_init(struct drm_modeset_lock *lock) | |
367 | { | |
368 | ww_mutex_init(&lock->mutex, &crtc_ww_class); | |
369 | INIT_LIST_HEAD(&lock->head); | |
2dba5eb1 | 370 | __drm_stack_depot_init(); |
35cf0350 RC |
371 | } |
372 | EXPORT_SYMBOL(drm_modeset_lock_init); | |
373 | ||
51fd371b RC |
374 | /** |
375 | * drm_modeset_lock - take modeset lock | |
376 | * @lock: lock to take | |
377 | * @ctx: acquire ctx | |
378 | * | |
fc2157b6 | 379 | * If @ctx is not NULL, then its ww acquire context is used and the |
51fd371b RC |
380 | * lock will be tracked by the context and can be released by calling |
381 | * drm_modeset_drop_locks(). If -EDEADLK is returned, this means a | |
382 | * deadlock scenario has been detected and it is an error to attempt | |
383 | * to take any more locks without first calling drm_modeset_backoff(). | |
fc2157b6 | 384 | * |
6f8bcc74 ML |
385 | * If the @ctx is not NULL and initialized with |
386 | * %DRM_MODESET_ACQUIRE_INTERRUPTIBLE, this function will fail with | |
387 | * -ERESTARTSYS when interrupted. | |
388 | * | |
fc2157b6 | 389 | * If @ctx is NULL then the function call behaves like a normal, |
6f8bcc74 | 390 | * uninterruptible non-nesting mutex_lock() call. |
51fd371b RC |
391 | */ |
392 | int drm_modeset_lock(struct drm_modeset_lock *lock, | |
393 | struct drm_modeset_acquire_ctx *ctx) | |
394 | { | |
395 | if (ctx) | |
6f8bcc74 | 396 | return modeset_lock(lock, ctx, ctx->interruptible, false); |
51fd371b RC |
397 | |
398 | ww_mutex_lock(&lock->mutex, NULL); | |
399 | return 0; | |
400 | } | |
401 | EXPORT_SYMBOL(drm_modeset_lock); | |
402 | ||
403 | /** | |
6f8bcc74 | 404 | * drm_modeset_lock_single_interruptible - take a single modeset lock |
51fd371b | 405 | * @lock: lock to take |
51fd371b | 406 | * |
6f8bcc74 ML |
407 | * This function behaves as drm_modeset_lock() with a NULL context, |
408 | * but performs interruptible waits. | |
409 | * | |
410 | * This function returns 0 on success, or -ERESTARTSYS when interrupted. | |
51fd371b | 411 | */ |
6f8bcc74 | 412 | int drm_modeset_lock_single_interruptible(struct drm_modeset_lock *lock) |
51fd371b | 413 | { |
51fd371b RC |
414 | return ww_mutex_lock_interruptible(&lock->mutex, NULL); |
415 | } | |
6f8bcc74 | 416 | EXPORT_SYMBOL(drm_modeset_lock_single_interruptible); |
51fd371b RC |
417 | |
418 | /** | |
419 | * drm_modeset_unlock - drop modeset lock | |
420 | * @lock: lock to release | |
421 | */ | |
422 | void drm_modeset_unlock(struct drm_modeset_lock *lock) | |
423 | { | |
424 | list_del_init(&lock->head); | |
425 | ww_mutex_unlock(&lock->mutex); | |
426 | } | |
427 | EXPORT_SYMBOL(drm_modeset_unlock); | |
428 | ||
06eaae46 TR |
429 | /** |
430 | * drm_modeset_lock_all_ctx - take all modeset locks | |
431 | * @dev: DRM device | |
432 | * @ctx: lock acquisition context | |
433 | * | |
434 | * This function takes all modeset locks, suitable where a more fine-grained | |
435 | * scheme isn't (yet) implemented. | |
436 | * | |
d574528a | 437 | * Unlike drm_modeset_lock_all(), it doesn't take the &drm_mode_config.mutex |
06eaae46 TR |
438 | * since that lock isn't required for modeset state changes. Callers which |
439 | * need to grab that lock too need to do so outside of the acquire context | |
440 | * @ctx. | |
441 | * | |
442 | * Locks acquired with this function should be released by calling the | |
443 | * drm_modeset_drop_locks() function on @ctx. | |
444 | * | |
b7ea04d2 SP |
445 | * See also: DRM_MODESET_LOCK_ALL_BEGIN() and DRM_MODESET_LOCK_ALL_END() |
446 | * | |
06eaae46 TR |
447 | * Returns: 0 on success or a negative error-code on failure. |
448 | */ | |
449 | int drm_modeset_lock_all_ctx(struct drm_device *dev, | |
450 | struct drm_modeset_acquire_ctx *ctx) | |
51fd371b | 451 | { |
b962a120 | 452 | struct drm_private_obj *privobj; |
51fd371b | 453 | struct drm_crtc *crtc; |
4d02e2de | 454 | struct drm_plane *plane; |
06eaae46 TR |
455 | int ret; |
456 | ||
457 | ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx); | |
458 | if (ret) | |
459 | return ret; | |
51fd371b | 460 | |
e4f62546 | 461 | drm_for_each_crtc(crtc, dev) { |
51fd371b RC |
462 | ret = drm_modeset_lock(&crtc->mutex, ctx); |
463 | if (ret) | |
464 | return ret; | |
465 | } | |
466 | ||
e4f62546 | 467 | drm_for_each_plane(plane, dev) { |
4d02e2de DV |
468 | ret = drm_modeset_lock(&plane->mutex, ctx); |
469 | if (ret) | |
470 | return ret; | |
471 | } | |
472 | ||
b962a120 RC |
473 | drm_for_each_privobj(privobj, dev) { |
474 | ret = drm_modeset_lock(&privobj->lock, ctx); | |
475 | if (ret) | |
476 | return ret; | |
477 | } | |
478 | ||
51fd371b RC |
479 | return 0; |
480 | } | |
06eaae46 | 481 | EXPORT_SYMBOL(drm_modeset_lock_all_ctx); |