From 415e6186f17136075f7cc825ba3835d005773637 Mon Sep 17 00:00:00 2001 From: Ben Skeggs Date: Fri, 23 Jul 2010 09:06:52 +1000 Subject: drm/nouveau: fix race condition when under memory pressure When VRAM is running out it's possible that the client's push buffers get evicted to main memory. When they're validated back in, the GPU may be used for the copy back to VRAM, but the existing synchronisation code only deals with inter-channel sync, not sync between PFIFO and PGRAPH on the same channel. This leads to PFIFO fetching from command buffers that haven't quite been copied by PGRAPH yet. This patch marks push buffers as so, and forces any GPU-assisted buffer moves to be done on a different channel, which triggers the correct synchronisation to happen before we submit them. Signed-off-by: Ben Skeggs --- drivers/gpu/drm/nouveau/nouveau_bo.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'drivers/gpu/drm/nouveau/nouveau_bo.c') diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c index 84f85183d04..f6f44779d82 100644 --- a/drivers/gpu/drm/nouveau/nouveau_bo.c +++ b/drivers/gpu/drm/nouveau/nouveau_bo.c @@ -36,6 +36,21 @@ #include #include +int +nouveau_bo_sync_gpu(struct nouveau_bo *nvbo, struct nouveau_channel *chan) +{ + struct nouveau_fence *prev_fence = nvbo->bo.sync_obj; + int ret; + + if (!prev_fence || nouveau_fence_channel(prev_fence) == chan) + return 0; + + spin_lock(&nvbo->bo.lock); + ret = ttm_bo_wait(&nvbo->bo, false, false, false); + spin_unlock(&nvbo->bo.lock); + return ret; +} + static void nouveau_bo_del_ttm(struct ttm_buffer_object *bo) { -- cgit v1.2.3-70-g09d2