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From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Mon, 15 Nov 2021 09:55:18 -0800
Message-ID: <CAKwvOd=AFLdyrdGSbREk9ent0iGjG_RmXH+VJXykNZ9WQUT_rw@mail.gmail.com>
Subject: Re: [PATCH 2/3] media: atomisp-gc2235: drop an unused var
To:     Dan Carpenter <dan.carpenter@oracle.com>
Cc:     Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
        linuxarm@huawei.com, mauro.chehab@huawei.com,
        Beatriz Martins de Carvalho 
        <martinsdecarvalhobeatriz@gmail.com>,
        Deepak R Varma <drv@mailo.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Tom Rix <trix@redhat.com>,
        Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>,
        linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
        linux-staging@lists.linux.dev, llvm@lists.linux.dev
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On Mon, Nov 15, 2021 at 1:29 AM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> On Thu, Nov 11, 2021 at 11:08:52PM +0000, Mauro Carvalho Chehab wrote:
> > Fix this clang Werror with W=1:
> >
> > drivers/staging/media/atomisp/i2c/atomisp-gc2235.c:573:6: error: variable 'ret' set but not used [-Werror,-Wunused-but-set-variable]
> >         int ret = -1;
> >             ^
> >
> > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> > ---
> >
>
> Looks good.
>
> There should be warning for "int x = -1;" followed by |= because that's
> a no-op OR assignment.
>
> I'm surprised that clang doesn't print errors about the other
> implementations of power_ctrl().

clang-tidy and scan-build will report dead stores.  You may have seen
patches from reports from Abaci Robot which is running those checks
continuously.

>
> drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c
>    448  static int power_ctrl(struct v4l2_subdev *sd, bool flag)
>    449  {
>    450          int ret;
>    451          struct mt9m114_device *dev = to_mt9m114_sensor(sd);
>    452
>    453          if (!dev || !dev->platform_data)
>    454                  return -ENODEV;
>    455
>    456          if (flag) {
>    457                  ret = dev->platform_data->v2p8_ctrl(sd, 1);
>    458                  if (ret == 0) {
>    459                          ret = dev->platform_data->v1p8_ctrl(sd, 1);
>    460                          if (ret)
>    461                                  ret = dev->platform_data->v2p8_ctrl(sd, 0);
>    462                  }
>    463          } else {
>    464                  ret = dev->platform_data->v2p8_ctrl(sd, 0);
>    465                  ret = dev->platform_data->v1p8_ctrl(sd, 0);
>                         ^^^^^^
>
>    466          }
>    467          return ret;
>    468  }
>    469
>    470  static int gpio_ctrl(struct v4l2_subdev *sd, bool flag)
>    471  {
>    472          int ret;
>    473          struct mt9m114_device *dev = to_mt9m114_sensor(sd);
>    474
>    475          if (!dev || !dev->platform_data)
>    476                  return -ENODEV;
>    477
>    478          /*
>    479           * Note: current modules wire only one GPIO signal (RESET#),
>    480           * but the schematic wires up two to the connector.  BIOS
>    481           * versions have been unfortunately inconsistent with which
>    482           * ACPI index RESET# is on, so hit both
>    483           */
>    484
>    485          if (flag) {
>    486                  ret = dev->platform_data->gpio0_ctrl(sd, 0);
>    487                  ret = dev->platform_data->gpio1_ctrl(sd, 0);
>                         ^^^^^^^
>
>    488                  msleep(60);
>    489                  ret |= dev->platform_data->gpio0_ctrl(sd, 1);
>    490                  ret |= dev->platform_data->gpio1_ctrl(sd, 1);
>    491          } else {
>
> regards,
> dan carpenter
>


-- 
Thanks,
~Nick Desaulniers