[PATCH AUTOSEL 5.2 119/185] media: aspeed-video: address a protential usage of an unitialized var

Sasha Levin
2019-09-22T18:53:13Z

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