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From: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
To: unlisted-recipients:; (no To-header on input)
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
	Linux Media Mailing List <linux-media@vger.kernel.org>,
	Mauro Carvalho Chehab <mchehab@infradead.org>,
	Hans Verkuil <hverkuil@xs4all.nl>
Subject: [PATCH 2/5] media: pwc-ctl: pChoose can't be NULL
Date: Mon, 25 Mar 2019 18:03:34 -0400	[thread overview]
Message-ID: <4f777d011bdd9e78fcf02701e89c8be457504a6c.1553551369.git.mchehab+samsung@kernel.org> (raw)
In-Reply-To: <cover.1553551369.git.mchehab+samsung@kernel.org>

The way the code works, compression will be a valid value (less or equal to 3)
on both set_video_mode_foo() calls at the beginning of the while() loop.

So, the value for pChoose can't be NULL.

Solves those smatch warnings:

	drivers/media/usb/pwc/pwc-ctrl.c: drivers/media/usb/pwc/pwc-ctrl.c:252 set_video_mode_Timon() warn: variable dereferenced before check 'pChoose' (see line 248)
	drivers/media/usb/pwc/pwc-ctrl.c: drivers/media/usb/pwc/pwc-ctrl.c:302 set_video_mode_Kiara() warn: variable dereferenced before check 'pChoose' (see line 298)

and simplifies the code a little bit.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
---
 drivers/media/usb/pwc/pwc-ctrl.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/media/usb/pwc/pwc-ctrl.c b/drivers/media/usb/pwc/pwc-ctrl.c
index 655cef39eb3d..b681a184ef87 100644
--- a/drivers/media/usb/pwc/pwc-ctrl.c
+++ b/drivers/media/usb/pwc/pwc-ctrl.c
@@ -242,14 +242,14 @@ static int set_video_mode_Timon(struct pwc_device *pdev, int size, int pixfmt,
 	fps = (frames / 5) - 1;
 
 	/* Find a supported framerate with progressively higher compression */
-	pChoose = NULL;
-	while (*compression <= 3) {
+	do {
 		pChoose = &Timon_table[size][fps][*compression];
 		if (pChoose->alternate != 0)
 			break;
 		(*compression)++;
-	}
-	if (pChoose == NULL || pChoose->alternate == 0)
+	} while (*compression <= 3);
+
+	if (pChoose->alternate == 0)
 		return -ENOENT; /* Not supported. */
 
 	if (send_to_cam)
@@ -279,7 +279,7 @@ static int set_video_mode_Timon(struct pwc_device *pdev, int size, int pixfmt,
 static int set_video_mode_Kiara(struct pwc_device *pdev, int size, int pixfmt,
 				int frames, int *compression, int send_to_cam)
 {
-	const struct Kiara_table_entry *pChoose = NULL;
+	const struct Kiara_table_entry *pChoose;
 	int fps, ret = 0;
 
 	if (size >= PSZ_MAX || *compression < 0 || *compression > 3)
@@ -293,13 +293,14 @@ static int set_video_mode_Kiara(struct pwc_device *pdev, int size, int pixfmt,
 	fps = (frames / 5) - 1;
 
 	/* Find a supported framerate with progressively higher compression */
-	while (*compression <= 3) {
+	do {
 		pChoose = &Kiara_table[size][fps][*compression];
 		if (pChoose->alternate != 0)
 			break;
 		(*compression)++;
-	}
-	if (pChoose == NULL || pChoose->alternate == 0)
+	} while (*compression <= 3);
+
+	if (pChoose->alternate == 0)
 		return -ENOENT; /* Not supported. */
 
 	/* Firmware bug: video endpoint is 5, but commands are sent to endpoint 4 */
-- 
2.20.1


  parent reply	other threads:[~2019-03-25 22:03 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-25 22:03 [PATCH 0/5] Fix smatch warnings Mauro Carvalho Chehab
2019-03-25 22:03 ` [PATCH 1/5] media: cx2341x: replace badly designed macros Mauro Carvalho Chehab
2019-03-25 22:03 ` Mauro Carvalho Chehab [this message]
2019-03-25 22:03 ` [PATCH 3/5] media: sti/delta: remove uneeded check Mauro Carvalho Chehab
2019-03-25 22:03 ` [PATCH 4/5] media: rcar-dma: p_set can't be NULL Mauro Carvalho Chehab
2019-03-26  8:55   ` Sergei Shtylyov
2019-03-25 22:03 ` [PATCH 5/5] media: hfi_parser: don't trick gcc with a wrong expected size Mauro Carvalho Chehab

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