From fa67ac84a33eeb5a3702970fe75083be79f460f9 Mon Sep 17 00:00:00 2001 From: Lucas Stach Date: Fri, 17 Nov 2017 16:35:32 +0100 Subject: [PATCH] drm/etnaviv: don't flush workqueue in etnaviv_gpu_wait_obj_inactive There is no need to synchronize with oustanding retire jobs if the object has gone idle. Retire jobs only ever change the object state from active to idle, not the other way around. The IOVA put race is uncritical, as the GEM_WAIT ioctl itself is holding a reference to the GEM object, so the retire worker will not pull the object into the CPU domain, which is the thing we are trying to guard against with etnaviv_gpu_wait_obj_inactive. The ordering of the various counts and waits may change a bit, but the userspace visible behavior at the bounds of the syscall are unchanged. Signed-off-by: Lucas Stach Reviewed-by: Philipp Zabel --- drivers/gpu/drm/etnaviv/etnaviv_gpu.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c index 95187ebe1660..3738383474fb 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c @@ -1295,17 +1295,12 @@ int etnaviv_gpu_wait_obj_inactive(struct etnaviv_gpu *gpu, ret = wait_event_interruptible_timeout(gpu->fence_event, !is_active(etnaviv_obj), remaining); - if (ret > 0) { - struct etnaviv_drm_private *priv = gpu->drm->dev_private; - - /* Synchronise with the retire worker */ - flush_workqueue(priv->wq); + if (ret > 0) return 0; - } else if (ret == -ERESTARTSYS) { + else if (ret == -ERESTARTSYS) return -ERESTARTSYS; - } else { + else return -ETIMEDOUT; - } } int etnaviv_gpu_pm_get_sync(struct etnaviv_gpu *gpu) -- GitLab