[PATCH 1/6] gpu: host1x: Wait for timeout worker completion on channel free

[Mikko Perttunen]

cdma_timeout_destroy() used cancel_delayed_work() to cancel pending
timeout work when destroying the CDMA. Usually this is fine, but
there is a narrow race condition where the timeout handler has started
execution but has not taken cdma->lock; the channel is freed causing
cdma_stop to take cdma->lock and flush the channel; host1x_cdma_deinit
then proceeds with deinitializing cdma while the handler is waiting to
take cdma->lock.

Therefore change cdma_timeout_destroy to use cancel_delayed_work_sync
instead to ensure any pending timeout work completes before proceeding.

Signed-off-by: Mikko Perttunen <mperttunen@xxxxxxxxxx>
---
 drivers/gpu/host1x/hw/cdma_hw.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/host1x/hw/cdma_hw.c b/drivers/gpu/host1x/hw/cdma_hw.c
index 3f3f0018eee0..ab714d221120 100644
--- a/drivers/gpu/host1x/hw/cdma_hw.c
+++ b/drivers/gpu/host1x/hw/cdma_hw.c
@@ -355,7 +355,7 @@ static int cdma_timeout_init(struct host1x_cdma *cdma)
 static void cdma_timeout_destroy(struct host1x_cdma *cdma)
 {
 	if (cdma->timeout.initialized)
-		cancel_delayed_work(&cdma->timeout.wq);
+		cancel_delayed_work_sync(&cdma->timeout.wq);
 
 	cdma->timeout.initialized = false;
 }

-- 
2.53.0