[PATCH 4.9 089/109] dma-buf/sw-sync: Fix the is-signaled test to handle u32 wraparound

From: Greg Kroah-Hartman
Date: Thu Dec 07 2017 - 08:53:38 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>

commit 61894b02716f122dd7662d5d89f5b2245ca551e2 upstream.

Use the canonical __dma_fence_is_later() to compare the fence seqno
against the timeline seqno to check if the fence is signaled.

Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Cc: Sean Paul <seanpaul@xxxxxxxxxxxx>
Cc: Gustavo Padovan <gustavo@xxxxxxxxxxx>
Reviewed-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
Signed-off-by: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxx>
Link: http://patchwork.freedesktop.org/patch/msgid/20170629125930.821-2-chris@xxxxxxxxxxxxxxxxxx
[s/dma_fence/fence/g - gregkh]
Cc: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/dma-buf/sw_sync.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/dma-buf/sw_sync.c
+++ b/drivers/dma-buf/sw_sync.c
@@ -219,7 +219,7 @@ static bool timeline_fence_signaled(stru
{
struct sync_timeline *parent = fence_parent(fence);

- return (fence->seqno > parent->value) ? false : true;
+ return !__fence_is_later(fence->seqno, parent->value);
}

static bool timeline_fence_enable_signaling(struct fence *fence)