From: Varun Wadekar <vwadekar@nvidia.com>
Date: Tue, 23 Nov 2010 14:33:02 +0000 (+0530)
Subject: tegra: video: host: fix race condition in hostintr wait list
X-Git-Tag: firefly_0821_release~9833^2~88^2~2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=c6b65e02b3026bd77bf3a464d07d19f39f425070;p=firefly-linux-kernel-4.4.55.git

tegra: video: host: fix race condition in hostintr wait list

Change-Id: I5e58f5fe8935741441e2b30f585bb997b6317d3d
Author: Alex Frid <afrid@nvidia.com>
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
---

diff --git a/drivers/video/tegra/host/nvhost_intr.c b/drivers/video/tegra/host/nvhost_intr.c
index 848d8b1e84e0..007aaed9909f 100644
--- a/drivers/video/tegra/host/nvhost_intr.c
+++ b/drivers/video/tegra/host/nvhost_intr.c
@@ -178,8 +178,7 @@ static void run_handlers(struct list_head completed[NVHOST_INTR_ACTION_COUNT])
 		list_for_each_entry_safe(waiter, next, head, list) {
 			list_del(&waiter->list);
 			handler(waiter);
-			atomic_set(&waiter->state, WLS_HANDLED);
-			smp_wmb();
+			WARN_ON(atomic_xchg(&waiter->state, WLS_HANDLED) != WLS_REMOVED);
 			kref_put(&waiter->refcount, waiter_release);
 		}
 	}