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From: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
To: unlisted-recipients:; (no To-header on input)
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
	Antti Palosaari <crope@iki.fi>,
	linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 03/38] media: qt1010: fix usage of unititialized value
Date: Wed,  2 Sep 2020 18:10:06 +0200	[thread overview]
Message-ID: <b14f07b9c89456001f4d9c1ce7a66d5ebea40fdf.1599062230.git.mchehab+huawei@kernel.org> (raw)
In-Reply-To: <cover.1599062230.git.mchehab+huawei@kernel.org>

As pointed by smatch:

	drivers/media/tuners/qt1010.c:239 qt1010_init_meas1() error: uninitialized symbol 'val2'.
	drivers/media/tuners/qt1010.c:273 qt1010_init_meas2() error: uninitialized symbol 'val'.

The logic is ok, but it is hard for static analyzers
to parse it, as it depends on a value read in the middle
of a loop.

Also, it takes a while for humans to verify.

Re-write the first function to use a more direct way.

At the second one, I opted to just initialize the read var,
in order to shut up the report.

While here, address a few coding style issues at the
function code.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 drivers/media/tuners/qt1010.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/drivers/media/tuners/qt1010.c b/drivers/media/tuners/qt1010.c
index e48faf942830..3853a3d43d4f 100644
--- a/drivers/media/tuners/qt1010.c
+++ b/drivers/media/tuners/qt1010.c
@@ -222,23 +222,24 @@ static int qt1010_init_meas1(struct qt1010_priv *priv,
 		{ QT1010_WR, reg, reg_init_val },
 		{ QT1010_WR, 0x1e, 0x00 },
 		{ QT1010_WR, 0x1e, oper },
-		{ QT1010_RD, reg, 0xff }
 	};
 
 	for (i = 0; i < ARRAY_SIZE(i2c_data); i++) {
-		if (i2c_data[i].oper == QT1010_WR) {
-			err = qt1010_writereg(priv, i2c_data[i].reg,
-					      i2c_data[i].val);
-		} else {
-			err = qt1010_readreg(priv, i2c_data[i].reg, &val2);
-		}
-		if (err) return err;
+		err = qt1010_writereg(priv, i2c_data[i].reg,
+				      i2c_data[i].val);
+		if (err)
+			return err;
 	}
 
+	err = qt1010_readreg(priv, reg, &val2);
+	if (err)
+		return err;
 	do {
 		val1 = val2;
 		err = qt1010_readreg(priv, reg, &val2);
-		if (err) return err;
+		if (err)
+			return err;
+
 		dev_dbg(&priv->i2c->dev, "%s: compare reg:%02x %02x %02x\n",
 				__func__, reg, val1, val2);
 	} while (val1 != val2);
@@ -250,7 +251,7 @@ static int qt1010_init_meas1(struct qt1010_priv *priv,
 static int qt1010_init_meas2(struct qt1010_priv *priv,
 			    u8 reg_init_val, u8 *retval)
 {
-	u8 i, val;
+	u8 i, val = 0xff;
 	int err;
 	qt1010_i2c_oper_t i2c_data[] = {
 		{ QT1010_WR, 0x07, reg_init_val },
@@ -261,6 +262,7 @@ static int qt1010_init_meas2(struct qt1010_priv *priv,
 		{ QT1010_WR, 0x1e, 0x00 },
 		{ QT1010_WR, 0x22, 0xff }
 	};
+
 	for (i = 0; i < ARRAY_SIZE(i2c_data); i++) {
 		if (i2c_data[i].oper == QT1010_WR) {
 			err = qt1010_writereg(priv, i2c_data[i].reg,
@@ -268,7 +270,8 @@ static int qt1010_init_meas2(struct qt1010_priv *priv,
 		} else {
 			err = qt1010_readreg(priv, i2c_data[i].reg, &val);
 		}
-		if (err) return err;
+		if (err)
+			return err;
 	}
 	*retval = val;
 	return 0;
-- 
2.26.2


  parent reply	other threads:[~2020-09-02 16:11 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-02 16:10 [PATCH 00/38] media sparse/smatch warn fixes Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 01/38] media: tda10086: cleanup symbol_rate setting logic Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 02/38] media: v4l2-ioctl: avoid memory leaks on some time32 compat functions Mauro Carvalho Chehab
2020-09-02 16:26   ` Laurent Pinchart
2020-09-02 18:45   ` Arnd Bergmann
2020-09-03  6:01     ` Mauro Carvalho Chehab
2020-09-02 16:10 ` Mauro Carvalho Chehab [this message]
2020-09-02 16:10 ` [PATCH 04/38] media: av7110_v4l: avoid a typecast Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 05/38] media: wl128x: get rid of a potential spectre issue Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 06/38] media: venus: place extern venus_fw_debug on a header file Mauro Carvalho Chehab
2020-09-10 10:45   ` Stanimir Varbanov
2020-09-02 16:10 ` [PATCH 07/38] media: tda10021: avoid casts when using symbol_rate Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 08/38] media: serial_ir: use the right type for a dma address Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 09/38] media: vivid: move the detection part out of vivid_create_instance Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 10/38] media: vivid: place the logic which disables ioctl on a separate function Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 11/38] media: vivid: move set_capabilities logic to " Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 12/38] media: vivid: place dt timings init code on " Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 13/38] media: vivid: move the create queues to " Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 14/38] media: vivid: move the devnode creation logic " Mauro Carvalho Chehab
2020-09-02 21:57   ` kernel test robot
2020-09-03  0:31   ` kernel test robot
2020-09-02 16:10 ` [PATCH 15/38] media: vivid: fix error path Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 16/38] media: videobuf-dma-sg: number of pages should be unsigned long Mauro Carvalho Chehab
2020-09-03  7:49   ` John Hubbard
2020-09-02 16:10 ` [PATCH 17/38] media: cx25821-alsa: " Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 18/38] media: cx23885-alsa: " Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 19/38] media: cx88-alsa: " Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 20/38] media: saa7134-alsa.c: " Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 21/38] media: dvb-ttusb-budget: don't use stack for USB transfers Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 22/38] media: dvb-ttusb-budget: cleanup printk logic Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 23/38] media: saa7134: avoid a shift overflow Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 24/38] media: atomisp: fix casts at atomisp_compat_ioctl32.c Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 25/38] media: atomisp: get rid of some unused code Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 26/38] media: atomisp: cleanup ifdefs from ia_css_debug.c Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 27/38] media: atomisp: get rid of version-dependent globals Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 28/38] media: atomisp: get rid of isys_dma.h and isys_dma_local.h Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 29/38] media: atomisp: get rid of ibuf_ctrl abstraction Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 30/38] media: atomisp: don't check for ISP version for includes Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 31/38] media: atomisp: unify INPUT error return type Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 32/38] media: atomisp: de-duplicate names at *_input_system_global.h Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 33/38] media: atomisp: reorder functions at pixelgen_private.h Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 34/38] media: atomisp: remove compile-time tests from input_system_global.h Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 35/38] media: atomisp: fix some bad indents Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 36/38] media: atomisp: csi_rx.c: add a missing includes Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 37/38] media: atomisp: atomisp_gmin_platform: check before use Mauro Carvalho Chehab
2020-09-02 16:10 ` [PATCH 38/38] media: atomisp: cleanup isys_irq headers Mauro Carvalho Chehab
2020-09-07 10:17 ` [PATCH 00/38] media sparse/smatch warn fixes Hans Verkuil

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