This is a note to let you know that I've just added the patch titled drm/syncobj: fix DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-syncobj-fix-drm_syncobj_wait_flags_wait_availabl.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 383766e64feb4fce1934f7687435c9a620e406a5 Author: Erik Kurzinger <ekurzinger@xxxxxxxxxx> Date: Wed Aug 16 09:26:05 2023 -0700 drm/syncobj: fix DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE [ Upstream commit 101c9f637efa1655f55876644d4439e552267527 ] If DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT is invoked with the DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE flag set but no fence has yet been submitted for the given timeline point the call will fail immediately with EINVAL. This does not match the intended behavior where the call should wait until the fence has been submitted (or the timeout expires). The following small example program illustrates the issue. It should wait for 5 seconds and then print ETIME, but instead it terminates right away after printing EINVAL. #include <stdio.h> #include <fcntl.h> #include <time.h> #include <errno.h> #include <xf86drm.h> int main(void) { int fd = open("/dev/dri/card0", O_RDWR); uint32_t syncobj; drmSyncobjCreate(fd, 0, &syncobj); struct timespec ts; clock_gettime(CLOCK_MONOTONIC, &ts); uint64_t point = 1; if (drmSyncobjTimelineWait(fd, &syncobj, &point, 1, ts.tv_sec * 1000000000 + ts.tv_nsec + 5000000000, // 5s DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE, NULL)) { printf("drmSyncobjTimelineWait failed %d\n", errno); } } Fixes: 01d6c3578379 ("drm/syncobj: add support for timeline point wait v8") Signed-off-by: Erik Kurzinger <ekurzinger@xxxxxxxxxx> Reviewed by: Simon Ser <contact@xxxxxxxxxxx> Signed-off-by: Simon Ser <contact@xxxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/1fac96f1-2f3f-f9f9-4eb0-340f27a8f6c0@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c index e558381c4c96e..8b155e3377cfe 100644 --- a/drivers/gpu/drm/drm_syncobj.c +++ b/drivers/gpu/drm/drm_syncobj.c @@ -921,7 +921,8 @@ static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs, fence = drm_syncobj_fence_get(syncobjs[i]); if (!fence || dma_fence_chain_find_seqno(&fence, points[i])) { dma_fence_put(fence); - if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) { + if (flags & (DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT | + DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)) { continue; } else { timeout = -EINVAL;