6.6-stable review patch. If anyone has any objections, please let me know.
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From: Alex Constantino dreaming.about.electric.sheep@gmail.com
[ Upstream commit 07ed11afb68d94eadd4ffc082b97c2331307c5ea ]
This reverts commit 5a838e5d5825c85556011478abde708251cc0776.
Changes from commit 5a838e5d5825 ("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 d72277b6c37d ("dma-buf: nuke DMA_FENCE_TRACE macros v2").
Fixes: 5a838e5d5825 ("drm/qxl: simplify qxl_fence_wait") Link: https://lore.kernel.org/regressions/ZTgydqRlK6WX_b29@eldamar.lan/ Reported-by: Timo Lindfors timo.lindfors@iki.fi Closes: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1054514 Signed-off-by: Alex Constantino dreaming.about.electric.sheep@gmail.com Signed-off-by: Maxime Ripard mripard@kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20240404181448.1643-2-dreaming... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/qxl/qxl_release.c | 50 +++++++++++++++++++++++++++---- include/linux/dma-fence.h | 7 +++++ 2 files changed, 52 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/qxl/qxl_release.c b/drivers/gpu/drm/qxl/qxl_release.c index 368d26da0d6a2..9febc8b73f09e 100644 --- a/drivers/gpu/drm/qxl/qxl_release.c +++ b/drivers/gpu/drm/qxl/qxl_release.c @@ -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;
- if (!wait_event_timeout(qdev->release_event, - (dma_fence_is_signaled(fence) || - (qxl_io_notify_oom(qdev), 0)), - timeout)) - return 0; +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 (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; diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index b3772edca2e6e..fd4a823ce3cdb 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -681,4 +681,11 @@ 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 */