[PATCH] libcamera: fix maybe-uninitialized error

[Naushir Patuck]

Hi Stefan,

On Thu, 27 Jun 2024 at 14:37, Stefan Klug <stefan.klug at ideasonboard.com> wrote:
>
> The gcc used in my current buildroot (Version 12.3) errors out with
> -Wmaybe-uninitialized. Fix that.
>
> Signed-off-by: Stefan Klug <stefan.klug at ideasonboard.com>
> ---
>
> @Naush: Could you have a look at the rpi specific changes? Specifically
> I'm not sure if the change in AwbConfig::read() is correct. It was
> unclear to me if there are cases where line 125 should return 0 even
> though a error got logged one line above.

I think the original error handling is probably wrong and we need
something like:

diff --git a/src/ipa/rpi/controller/rpi/awb.cpp
b/src/ipa/rpi/controller/rpi/awb.cpp
index 5ae0c2fad6e9..81f700dba2c7 100644
--- a/src/ipa/rpi/controller/rpi/awb.cpp
+++ b/src/ipa/rpi/controller/rpi/awb.cpp
@@ -121,7 +121,7 @@ int AwbConfig::read(const libcamera::YamlObject &params)
                }
                if (priors.empty()) {
                        LOG(RPiAwb, Error) << "AwbConfig: no AWB
priors configured";
-                       return ret;
+                       return -EINVAL;
                }

Feel free to make that change as part of this commt, or I can submit a
separate patch.

Your changes look good to me otherwise.

Reviewed-by: Naushir Patuck <naush at raspberrypi.com>


>
> Regards,
> Stefan
>
>
>  src/ipa/libipa/exposure_mode_helper.cpp   | 15 ++++++---------
>  src/ipa/rpi/controller/rpi/awb.cpp        |  2 +-
>  src/libcamera/device_enumerator_sysfs.cpp |  2 +-
>  src/libcamera/pipeline/rpi/vc4/vc4.cpp    |  2 +-
>  4 files changed, 9 insertions(+), 12 deletions(-)
>
> diff --git a/src/ipa/libipa/exposure_mode_helper.cpp b/src/ipa/libipa/exposure_mode_helper.cpp
> index 683a564a01c8..9d1387636d05 100644
> --- a/src/ipa/libipa/exposure_mode_helper.cpp
> +++ b/src/ipa/libipa/exposure_mode_helper.cpp
> @@ -166,7 +166,7 @@ ExposureModeHelper::splitExposure(utils::Duration exposure) const
>                 return { minShutter_, minGain_, exposure / (minShutter_ * minGain_) };
>
>         utils::Duration shutter;
> -       double stageGain;
> +       double stageGain = 1.0;
>         double gain;
>
>         for (unsigned int stage = 0; stage < gains_.size(); stage++) {
> @@ -198,15 +198,12 @@ ExposureModeHelper::splitExposure(utils::Duration exposure) const
>         }
>
>         /*
> -        * From here on all we can do is max out the shutter time, followed by
> -        * the analogue gain. If we still haven't achieved the target we send
> -        * the rest of the exposure time to digital gain. If we were given no
> -        * stages to use then set stageGain to 1.0 so that shutter time is maxed
> -        * before gain touched at all.
> +        * From here on all we can do is max out the shutter time, followed by the
> +        * analogue gain. If we still haven't achieved the target we send the rest
> +        * of the exposure time to digital gain. If we were given no stages to use
> +        * then the default stageGain of 1.0 is used so that shutter time is maxed
> +        * before gain is touched at all.
>          */
> -       if (gains_.empty())
> -               stageGain = 1.0;
> -
>         shutter = clampShutter(exposure / clampGain(stageGain));
>         gain = clampGain(exposure / shutter);
>
> diff --git a/src/ipa/rpi/controller/rpi/awb.cpp b/src/ipa/rpi/controller/rpi/awb.cpp
> index 003c8fa137f3..3503a5ab9218 100644
> --- a/src/ipa/rpi/controller/rpi/awb.cpp
> +++ b/src/ipa/rpi/controller/rpi/awb.cpp
> @@ -91,7 +91,7 @@ static int readCtCurve(ipa::Pwl &ctR, ipa::Pwl &ctB, const libcamera::YamlObject
>
>  int AwbConfig::read(const libcamera::YamlObject &params)
>  {
> -       int ret;
> +       int ret = 0;
>
>         bayes = params["bayes"].get<int>(1);
>         framePeriod = params["frame_period"].get<uint16_t>(10);
> diff --git a/src/libcamera/device_enumerator_sysfs.cpp b/src/libcamera/device_enumerator_sysfs.cpp
> index fc33ba52b813..7866885c0f73 100644
> --- a/src/libcamera/device_enumerator_sysfs.cpp
> +++ b/src/libcamera/device_enumerator_sysfs.cpp
> @@ -33,7 +33,7 @@ int DeviceEnumeratorSysfs::init()
>  int DeviceEnumeratorSysfs::enumerate()
>  {
>         struct dirent *ent;
> -       DIR *dir;
> +       DIR *dir = nullptr;
>
>         static const char * const sysfs_dirs[] = {
>                 "/sys/subsystem/media/devices",
> diff --git a/src/libcamera/pipeline/rpi/vc4/vc4.cpp b/src/libcamera/pipeline/rpi/vc4/vc4.cpp
> index 4a89e35f5d7b..e5b6ef2b37cd 100644
> --- a/src/libcamera/pipeline/rpi/vc4/vc4.cpp
> +++ b/src/libcamera/pipeline/rpi/vc4/vc4.cpp
> @@ -802,7 +802,7 @@ void Vc4CameraData::ispInputDequeue(FrameBuffer *buffer)
>  void Vc4CameraData::ispOutputDequeue(FrameBuffer *buffer)
>  {
>         RPi::Stream *stream = nullptr;
> -       unsigned int index;
> +       unsigned int index = 0;
>
>         if (!isRunning())
>                 return;
> --
> 2.43.0
>