[PATCH AUTOSEL 5.14 010/252] dma-buf: fix dma_resv_test_signaled test_all handling v2

From: Sasha Levin
Date: Wed Sep 08 2021 - 21:46:49 EST


From: Christian König <christian.koenig@xxxxxxx>

[ Upstream commit 9d38814d1e346ea37a51cbf31f4424c9d059459e ]

As the name implies if testing all fences is requested we
should indeed test all fences and not skip the exclusive
one because we see shared ones.

v2: fix logic once more

Signed-off-by: Christian König <christian.koenig@xxxxxxx>
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20210702111642.17259-3-christian.koenig@xxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/dma-buf/dma-resv.c | 33 ++++++++++++---------------------
1 file changed, 12 insertions(+), 21 deletions(-)

diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index f26c71747d43..e744fd87c63c 100644
--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -615,25 +615,21 @@ static inline int dma_resv_test_signaled_single(struct dma_fence *passed_fence)
*/
bool dma_resv_test_signaled(struct dma_resv *obj, bool test_all)
{
- unsigned int seq, shared_count;
+ struct dma_fence *fence;
+ unsigned int seq;
int ret;

rcu_read_lock();
retry:
ret = true;
- shared_count = 0;
seq = read_seqcount_begin(&obj->seq);

if (test_all) {
struct dma_resv_list *fobj = dma_resv_shared_list(obj);
- unsigned int i;
-
- if (fobj)
- shared_count = fobj->shared_count;
+ unsigned int i, shared_count;

+ shared_count = fobj ? fobj->shared_count : 0;
for (i = 0; i < shared_count; ++i) {
- struct dma_fence *fence;
-
fence = rcu_dereference(fobj->shared[i]);
ret = dma_resv_test_signaled_single(fence);
if (ret < 0)
@@ -641,24 +637,19 @@ bool dma_resv_test_signaled(struct dma_resv *obj, bool test_all)
else if (!ret)
break;
}
-
- if (read_seqcount_retry(&obj->seq, seq))
- goto retry;
}

- if (!shared_count) {
- struct dma_fence *fence_excl = dma_resv_excl_fence(obj);
-
- if (fence_excl) {
- ret = dma_resv_test_signaled_single(fence_excl);
- if (ret < 0)
- goto retry;
+ fence = dma_resv_excl_fence(obj);
+ if (ret && fence) {
+ ret = dma_resv_test_signaled_single(fence);
+ if (ret < 0)
+ goto retry;

- if (read_seqcount_retry(&obj->seq, seq))
- goto retry;
- }
}

+ if (read_seqcount_retry(&obj->seq, seq))
+ goto retry;
+
rcu_read_unlock();
return ret;
}
--
2.30.2