From: Dongchun Zhu <dongchun.zhu@mediatek.com>
To: Arnd Bergmann <arnd@kernel.org>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>,
Nathan Chancellor <natechancellor@gmail.com>,
Nick Desaulniers <ndesaulniers@google.com>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Sakari Ailus <sakari.ailus@linux.intel.com>,
Arnd Bergmann <arnd@arndb.de>, <linux-media@vger.kernel.org>,
<linux-kernel@vger.kernel.org>,
<clang-built-linux@googlegroups.com>, <tfiga@google.com>,
<sj.huang@mediatek.com>
Subject: Re: [PATCH] media: i2c: fix an uninitialized error code
Date: Fri, 4 Dec 2020 10:10:28 +0800 [thread overview]
Message-ID: <1607047828.4733.172.camel@mhfsdcap03> (raw)
In-Reply-To: <20201203222956.1091606-1-arnd@kernel.org>
Hi Arnd,
Thanks for the patch.
On Thu, 2020-12-03 at 23:29 +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
>
> Clang points out that the error handling in ov02a10_s_stream() is
> broken, and just returns a random error code:
>
> drivers/media/i2c/ov02a10.c:537:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
> if (ov02a10->streaming == on)
> ^~~~~~~~~~~~~~~~~~~~~~~~
> drivers/media/i2c/ov02a10.c:568:9: note: uninitialized use occurs here
> return ret;
> ^~~
> drivers/media/i2c/ov02a10.c:537:2: note: remove the 'if' if its condition is always false
> if (ov02a10->streaming == on)
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/media/i2c/ov02a10.c:533:9: note: initialize the variable 'ret' to silence this warning
> int ret;
>
> I assume that -EBUSY is the intended error code, so use that.
>
> Fixes: 91807efbe8ec ("media: i2c: add OV02A10 image sensor driver")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> drivers/media/i2c/ov02a10.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/i2c/ov02a10.c b/drivers/media/i2c/ov02a10.c
> index 391718136ade..7ee9c904d9b5 100644
> --- a/drivers/media/i2c/ov02a10.c
> +++ b/drivers/media/i2c/ov02a10.c
> @@ -534,8 +534,10 @@ static int ov02a10_s_stream(struct v4l2_subdev *sd, int on)
>
> mutex_lock(&ov02a10->mutex);
>
> - if (ov02a10->streaming == on)
> + if (ov02a10->streaming == on) {
> + ret = -EBUSY;
> goto unlock_and_return;
> + }
>
> if (on) {
> ret = pm_runtime_get_sync(&client->dev);
Only if sensor fails to stream on, ret can return a negative error code.
Thus ret above needs to be initialized to '0'.
Also you could fix the clang error like this.
static int ov02a10_s_stream(struct v4l2_subdev *sd, int on)
{
struct ov02a10 *ov02a10 = to_ov02a10(sd);
...
int ret = 0;
...
if (ov02a10->streaming == on)
goto unlock_and_return;
...
}
next prev parent reply other threads:[~2020-12-04 2:11 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-03 22:29 [PATCH] media: i2c: fix an uninitialized error code Arnd Bergmann
2020-12-04 2:10 ` Dongchun Zhu [this message]
2020-12-04 8:22 ` Arnd Bergmann
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