On 2017年07月31日 23:39, Deucher, Alexander wrote:
-----Original Message-----
From: Christian König [mailto:deathsim...@vodafone.de]
Sent: Monday, July 31, 2017 10:13 AM
To: linux-media@vger.kernel.org; dri-de...@lists.freedesktop.org; linaro-
mm-...@lists.linaro.org; Zhou, David(ChunMing); Deucher, Alexander
Subject: Re: [PATCH] dma-buf: fix reservation_object_wait_timeout_rcu to
wait correctly v2
Ping, what do you guys think of that?
Seems reasonable to me.
Reviewed-by: Alex Deucher <alexander.deuc...@amd.com>
Reviewed-by: Chunming Zhou <david1.z...@amd.com> as well.
Am 25.07.2017 um 15:35 schrieb Christian König:
From: Christian König <christian.koe...@amd.com>
With hardware resets in mind it is possible that all shared fences are
signaled, but the exlusive isn't. Fix waiting for everything in this situation.
v2: make sure we always wait for the exclusive fence
Signed-off-by: Christian König <christian.koe...@amd.com>
---
drivers/dma-buf/reservation.c | 33 +++++++++++++++------------------
1 file changed, 15 insertions(+), 18 deletions(-)
diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c
index 393817e..9d4316d 100644
--- a/drivers/dma-buf/reservation.c
+++ b/drivers/dma-buf/reservation.c
@@ -373,12 +373,25 @@ long reservation_object_wait_timeout_rcu(struct
reservation_object *obj,
long ret = timeout ? timeout : 1;
retry:
- fence = NULL;
shared_count = 0;
seq = read_seqcount_begin(&obj->seq);
rcu_read_lock();
- if (wait_all) {
+ fence = rcu_dereference(obj->fence_excl);
+ if (fence && !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence-
flags)) {
+ if (!dma_fence_get_rcu(fence))
+ goto unlock_retry;
+
+ if (dma_fence_is_signaled(fence)) {
+ dma_fence_put(fence);
+ fence = NULL;
+ }
+
+ } else {
+ fence = NULL;
+ }
+
+ if (!fence && wait_all) {
struct reservation_object_list *fobj =
rcu_dereference(obj-
fence);
@@ -405,22 +418,6 @@ long reservation_object_wait_timeout_rcu(struct
reservation_object *obj,
}
}
- if (!shared_count) {
- struct dma_fence *fence_excl = rcu_dereference(obj-
fence_excl);
-
- if (fence_excl &&
- !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
- &fence_excl->flags)) {
- if (!dma_fence_get_rcu(fence_excl))
- goto unlock_retry;
-
- if (dma_fence_is_signaled(fence_excl))
- dma_fence_put(fence_excl);
- else
- fence = fence_excl;
- }
- }
-
rcu_read_unlock();
if (fence) {
if (read_seqcount_retry(&obj->seq, seq)) {
