On 2017年07月31日 23:39, Deucher, Alexander wrote:

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-----Original Message----- From: Christian König [mailto:deathsimple@vodafone.de] Sent: Monday, July 31, 2017 10:13 AM To: linux-media@vger.kernel.org; dri-devel@lists.freedesktop.org; linaro- mm-sig@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.deucher@amd.com

Reviewed-by: Chunming Zhou david1.zhou@amd.com as well.

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Am 25.07.2017 um 15:35 schrieb Christian König:

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From: Christian König christian.koenig@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.koenig@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,

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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)) {