From 780d815dcc9b34d93ae69385a8465c38d423ff0f Mon Sep 17 00:00:00 2001

From: Tom Rix <trix@redhat.com>

Date: Mon, 10 Aug 2020 21:25:18 +0200

Subject: [PATCH] media: tw5864: check status of tw5864_frameinterval_get

Git-commit: 780d815dcc9b34d93ae69385a8465c38d423ff0f

Patch-mainline: v5.10-rc1

References: git-fixes

clang static analysis reports this problem

tw5864-video.c:773:32: warning: The left expression of the compound

  assignment is an uninitialized value.

  The computed value will also be garbage

        fintv->stepwise.max.numerator *= std_max_fps;

        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^

stepwise.max is set with frameinterval, which comes from

	ret = tw5864_frameinterval_get(input, &frameinterval);

	fintv->stepwise.step = frameinterval;

	fintv->stepwise.min = frameinterval;

	fintv->stepwise.max = frameinterval;

	fintv->stepwise.max.numerator *= std_max_fps;

When tw5864_frameinterval_get() fails, frameinterval is not

set. So check the status and fix another similar problem.

Signed-off-by: Tom Rix <trix@redhat.com>

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Acked-by: Takashi Iwai <tiwai@suse.de>

---

 drivers/media/pci/tw5864/tw5864-video.c | 6 ++++++

 1 file changed, 6 insertions(+)

diff --git a/drivers/media/pci/tw5864/tw5864-video.c b/drivers/media/pci/tw5864/tw5864-video.c

index f4bc72bbe2c5..9131265c2b87 100644

--- a/drivers/media/pci/tw5864/tw5864-video.c

+++ b/drivers/media/pci/tw5864/tw5864-video.c

@@ -767,6 +767,9 @@ static int tw5864_enum_frameintervals(struct file *file, void *priv,

 	fintv->type = V4L2_FRMIVAL_TYPE_STEPWISE;

 	ret = tw5864_frameinterval_get(input, &frameinterval);

+	if (ret)

+		return ret;

+

 	fintv->stepwise.step = frameinterval;

 	fintv->stepwise.min = frameinterval;

 	fintv->stepwise.max = frameinterval;

@@ -785,6 +788,9 @@ static int tw5864_g_parm(struct file *file, void *priv,

 	cp->capability = V4L2_CAP_TIMEPERFRAME;

 	ret = tw5864_frameinterval_get(input, &cp->timeperframe);

+	if (ret)

+		return ret;

+

 	cp->timeperframe.numerator *= input->frame_interval;

 	cp->capturemode = 0;

 	cp->readbuffers = 2;

-- 

2.16.4