From 48f243c95bdb17c1453d48142abad6aabed339e5 Mon Sep 17 00:00:00 2001 From: Rob Clark Date: Sat, 25 Feb 2017 10:36:30 -0500 Subject: [PATCH] drm/msm: move submit fence wait out of struct_mutex Probably a symptom of needing finer grained locking, but if we wait on the incoming fence-fd (which could come from a different context) while holding struct_mutex, that blocks retire_worker so gpu fences cannot get signalled. This causes a problem if userspace manages to get more than a frame ahead, leaving the atomic-commit worker blocked waiting on fences that cannot be signaled because submit is blocked waiting for a fence signalled from vblank (after the atomic commit which is blocked). If we start having multiple fence ctxs for the gpu, submit_fence_sync() would probably need to move outside of struct_mutex as well. Signed-off-by: Rob Clark --- drivers/gpu/drm/msm/msm_gem_submit.c | 39 +++++++++++++--------------- 1 file changed, 18 insertions(+), 21 deletions(-) diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c index 1172fe7a9252..1c545ebe6a5a 100644 --- a/drivers/gpu/drm/msm/msm_gem_submit.c +++ b/drivers/gpu/drm/msm/msm_gem_submit.c @@ -404,6 +404,24 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data, if (MSM_PIPE_FLAGS(args->flags) & ~MSM_SUBMIT_FLAGS) return -EINVAL; + if (args->flags & MSM_SUBMIT_FENCE_FD_IN) { + in_fence = sync_file_get_fence(args->fence_fd); + + if (!in_fence) + return -EINVAL; + + /* TODO if we get an array-fence due to userspace merging multiple + * fences, we need a way to determine if all the backing fences + * are from our own context.. + */ + + if (in_fence->context != gpu->fctx->context) { + ret = dma_fence_wait(in_fence, true); + if (ret) + return ret; + } + } + ret = mutex_lock_interruptible(&dev->struct_mutex); if (ret) return ret; @@ -431,27 +449,6 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data, if (ret) goto out; - if (args->flags & MSM_SUBMIT_FENCE_FD_IN) { - in_fence = sync_file_get_fence(args->fence_fd); - - if (!in_fence) { - ret = -EINVAL; - goto out; - } - - /* TODO if we get an array-fence due to userspace merging multiple - * fences, we need a way to determine if all the backing fences - * are from our own context.. - */ - - if (in_fence->context != gpu->fctx->context) { - ret = dma_fence_wait(in_fence, true); - if (ret) - goto out; - } - - } - if (!(args->fence & MSM_SUBMIT_NO_IMPLICIT)) { ret = submit_fence_sync(submit); if (ret) -- 2.20.1