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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Eddie James <eajames@linux.ibm.com>,
        Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.2 148/313] media: aspeed-video: address a protential usage of an unitialized var
Date:   Thu,  3 Oct 2019 17:52:06 +0200
Message-Id: <20191003154547.501267239@linuxfoundation.org>
In-Reply-To: <20191003154533.590915454@linuxfoundation.org>
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From: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

[ Upstream commit 31b8b0bd6e55c3ea5a08bb8141fa5d3c90600e3b ]

While this might not occur in practice, if the device is doing
the right thing, it would be teoretically be possible to have
both hsync_counter and vsync_counter negatives.

If this ever happen, ctrl will be undefined, but the driver
will still call:

	aspeed_video_update(video, VE_CTRL, 0, ctrl);

Change the code to prevent this to happen.

This was warned by cppcheck:

	[drivers/media/platform/aspeed-video.c:653]: (error) Uninitialized variable: ctrl

Reviewed-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/media/platform/aspeed-video.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c
index de0f192afa8b1..388c32a11345d 100644
--- a/drivers/media/platform/aspeed-video.c
+++ b/drivers/media/platform/aspeed-video.c
@@ -632,7 +632,7 @@ static void aspeed_video_check_and_set_polarity(struct aspeed_video *video)
 	}
 
 	if (hsync_counter < 0 || vsync_counter < 0) {
-		u32 ctrl;
+		u32 ctrl = 0;
 
 		if (hsync_counter < 0) {
 			ctrl = VE_CTRL_HSYNC_POL;
@@ -652,7 +652,8 @@ static void aspeed_video_check_and_set_polarity(struct aspeed_video *video)
 				V4L2_DV_VSYNC_POS_POL;
 		}
 
-		aspeed_video_update(video, VE_CTRL, 0, ctrl);
+		if (ctrl)
+			aspeed_video_update(video, VE_CTRL, 0, ctrl);
 	}
 }
 
-- 
2.20.1