Re: [V2, 2/2] media: i2c: Add DW9768 VCM driver

From: kbuild test robot <lkp@intel.com>
To: dongchun.zhu@mediatek.com
Cc: kbuild-all@01.org, mchehab@kernel.org,
	andriy.shevchenko@linux.intel.com, robh+dt@kernel.org,
	mark.rutland@arm.com, sakari.ailus@linux.intel.com,
	drinkcat@chromium.org, tfiga@chromium.org,
	matthias.bgg@gmail.com, bingbu.cao@intel.com,
	srv_heupstream@mediatek.com, linux-mediatek@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org, sj.huang@mediatek.com,
	linux-media@vger.kernel.org, devicetree@vger.kernel.org,
	sam.hung@mediatek.com, shengnan.wang@mediatek.com,
	dongchun.zhu@mediatek.com
Subject: Re: [V2, 2/2] media: i2c: Add DW9768 VCM driver
Date: Sun, 8 Sep 2019 06:12:50 +0800	[thread overview]
Message-ID: <201909080620.3L1t3Gn4%lkp@intel.com> (raw)
In-Reply-To: <20190905072142.14606-3-dongchun.zhu@mediatek.com>

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Hi,

I love your patch! Perhaps something to improve:

[auto build test WARNING on linuxtv-media/master]
[cannot apply to v5.3-rc7 next-20190904]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/dongchun-zhu-mediatek-com/media-i2c-dw9768-Add-DT-support-and-MAINTAINERS-entry/20190908-044622
base:   git://linuxtv.org/media_tree.git master
config: sh-allmodconfig (attached as .config)
compiler: sh4-linux-gcc (GCC) 7.4.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=7.4.0 make.cross ARCH=sh 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings

All warnings (new ones prefixed by >>):

   drivers/media/i2c/dw9768.c: In function 'dw9768_write_smbus':
>> drivers/media/i2c/dw9768.c:82:9: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized]
     return ret;
            ^~~

vim +/ret +82 drivers/media/i2c/dw9768.c

    70	
    71	static int dw9768_write_smbus(struct dw9768 *dw9768, unsigned char reg,
    72				      unsigned char value)
    73	{
    74		struct i2c_client *client = v4l2_get_subdevdata(&dw9768->sd);
    75		int ret;
    76	
    77		if (reg == DW9768_CMD_DELAY  && value == DW9768_CMD_DELAY)
    78			usleep_range(DW9768_CTRL_DELAY_US,
    79				     DW9768_CTRL_DELAY_US + 100);
    80		else
    81			ret = i2c_smbus_write_byte_data(client, reg, value);
  > 82		return ret;
    83	}
    84	

---
0-DAY kernel test infrastructure                Open Source Technology Center
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