Unverified Commit 07ed11af authored by Alex Constantino's avatar Alex Constantino Committed by Maxime Ripard
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Revert "drm/qxl: simplify qxl_fence_wait" 

This reverts commit 5a838e5d.

Changes from commit 5a838e5d ("drm/qxl: simplify qxl_fence_wait") would
result in a '[TTM] Buffer eviction failed' exception whenever it reached a
timeout.
Due to a dependency to DMA_FENCE_WARN this also restores some code deleted
by commit d72277b6 ("dma-buf: nuke DMA_FENCE_TRACE macros v2").

Fixes: 5a838e5d ("drm/qxl: simplify qxl_fence_wait")
Link: https://lore.kernel.org/regressions/ZTgydqRlK6WX_b29@eldamar.lan/


Reported-by: default avatarTimo Lindfors <timo.lindfors@iki.fi>
Closes: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1054514


Signed-off-by: default avatarAlex Constantino <dreaming.about.electric.sheep@gmail.com>
Signed-off-by: default avatarMaxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240404181448.1643-2-dreaming.about.electric.sheep@gmail.com
parent bc004f50

drivers/gpu/drm/qxl/qxl_release.c

+45 −5
Original line number Diff line number Diff line
@@ -58,16 +58,56 @@ static long qxl_fence_wait(struct dma_fence *fence, bool intr, 
			   signed long timeout)

{

	struct qxl_device *qdev;

	struct qxl_release *release;

	int count = 0, sc = 0;

	bool have_drawable_releases;

	unsigned long cur, end = jiffies + timeout;



	qdev = container_of(fence->lock, struct qxl_device, release_lock);

	release = container_of(fence, struct qxl_release, base);

	have_drawable_releases = release->type == QXL_RELEASE_DRAWABLE;



retry:

	sc++;



	if (dma_fence_is_signaled(fence))

		goto signaled;



	qxl_io_notify_oom(qdev);



	for (count = 0; count < 11; count++) {

		if (!qxl_queue_garbage_collect(qdev, true))

			break;



		if (dma_fence_is_signaled(fence))

			goto signaled;

	}



	if (!wait_event_timeout(qdev->release_event,

				(dma_fence_is_signaled(fence) ||

				 (qxl_io_notify_oom(qdev), 0)),

				timeout))

	if (dma_fence_is_signaled(fence))

		goto signaled;



	if (have_drawable_releases || sc < 4) {

		if (sc > 2)

			/* back off */

			usleep_range(500, 1000);



		if (time_after(jiffies, end))

			return 0;



		if (have_drawable_releases && sc > 300) {

			DMA_FENCE_WARN(fence,

				       "failed to wait on release %llu after spincount %d\n",

				       fence->context & ~0xf0000000, sc);

			goto signaled;

		}

		goto retry;

	}

	/*

	 * yeah, original sync_obj_wait gave up after 3 spins when

	 * have_drawable_releases is not set.

	 */



signaled:

	cur = jiffies;

	if (time_after(cur, end))

		return 0;

include/linux/dma-fence.h

+7 −0
Original line number Diff line number Diff line
@@ -682,4 +682,11 @@ static inline bool dma_fence_is_container(struct dma_fence *fence) 
	return dma_fence_is_array(fence) || dma_fence_is_chain(fence);

}



#define DMA_FENCE_WARN(f, fmt, args...) \

	do {								\

		struct dma_fence *__ff = (f);				\

		pr_warn("f %llu#%llu: " fmt, __ff->context, __ff->seqno,\

			 ##args);					\

	} while (0)



#endif /* __LINUX_DMA_FENCE_H */