[PATCH] v4l2: v4l2_camera_proxy: Fix VIDIOC_[GS]_PARM support

[Laurent Pinchart]

Hi Kieran,

On Mon, Nov 04, 2024 at 04:16:20PM +0000, Kieran Bingham wrote:
> Quoting Laurent Pinchart (2024-11-04 15:38:25)
> > v4l2-compliance reports an error due to VIDIOC_S_PARM being supported
> > without VIDIOC_G_PARM. Fix it by implementing VIDIOC_G_PARM. To satisfy
> > all compliance tests, VIDIOC_S_PARM also needs to be updated to properly
> > zero reserved fields.
> 
> Fixes tag ?

It has never worked. I can point to the commit that introduced the
compat layer.

> > Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> > ---
> >  src/v4l2/v4l2_camera.h         |  1 +
> >  src/v4l2/v4l2_camera_proxy.cpp | 63 ++++++++++++++++++++++++++++++++--
> >  src/v4l2/v4l2_camera_proxy.h   |  2 ++
> >  3 files changed, 64 insertions(+), 2 deletions(-)
> > 
> > diff --git a/src/v4l2/v4l2_camera.h b/src/v4l2/v4l2_camera.h
> > index e54371fb4e00..9bd161b909de 100644
> > --- a/src/v4l2/v4l2_camera.h
> > +++ b/src/v4l2/v4l2_camera.h
> > @@ -52,6 +52,7 @@ public:
> >                                   libcamera::StreamConfiguration *streamConfigOut);
> >  
> >         libcamera::ControlList &controls() { return controls_; }
> > +       const libcamera::ControlInfoMap &controlInfo() { return camera_->controls(); }
> >  
> >         int allocBuffers(unsigned int count);
> >         void freeBuffers();
> > diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp
> > index 5ac8df4cffef..559ffc6170b1 100644
> > --- a/src/v4l2/v4l2_camera_proxy.cpp
> > +++ b/src/v4l2/v4l2_camera_proxy.cpp
> > @@ -195,6 +195,29 @@ void V4L2CameraProxy::setFmtFromConfig(const StreamConfiguration &streamConfig)
> >         v4l2PixFormat_.xfer_func    = V4L2_XFER_FUNC_DEFAULT;
> >  
> >         sizeimage_ = streamConfig.frameSize;
> > +
> > +       const ControlInfoMap &controls = vcam_->controlInfo();
> > +       const auto &it = controls.find(&controls::FrameDurationLimits);
> > +
> > +       if (it != controls.end()) {
> > +               const int64_t duration = it->second.def().get<int64_t>();
> > +
> > +               v4l2TimePerFrame_.numerator = duration;
> > +               v4l2TimePerFrame_.denominator = 1000000;
> > +       } else {
> > +               /*
> > +                * Default to 30fps if the camera doesn't expose the
> > +                * FrameDurationLimits control.
> > +                *
> > +                * \todo Remove this once all pipeline handlers implement the
> > +                * control
> > +                */
> > +               LOG(V4L2Compat, Warning)
> > +                       << "Camera does not support FrameDurationLimits";
> > +
> > +               v4l2TimePerFrame_.numerator = 333333;
> > +               v4l2TimePerFrame_.denominator = 1000000;
> > +       }
> >  }
> >  
> >  void V4L2CameraProxy::querycap(std::shared_ptr<Camera> camera)
> > @@ -758,6 +781,22 @@ int V4L2CameraProxy::vidioc_streamoff(V4L2CameraFile *file, int *arg)
> >         return ret;
> >  }
> >  
> > +int V4L2CameraProxy::vidioc_g_parm(V4L2CameraFile *file, struct v4l2_streamparm *arg)
> > +{
> > +       LOG(V4L2Compat, Debug)
> > +               << "[" << file->description() << "] " << __func__ << "()";
> > +
> > +       if (!validateBufferType(arg->type))
> > +               return -EINVAL;
> > +
> > +       memset(&arg->parm, 0, sizeof(arg->parm));
> > +
> > +       arg->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
> 
> I guess this wasn't being handled at all before ?

G_PARM wasn't handled at all. Or is your comment about something else ?

> > +       arg->parm.capture.timeperframe = v4l2TimePerFrame_;
> 
> What does this return /before/ the camera is configured? Does it work ?

setFmtFromConfig() is called from the class constructor, so
v4l2TimePerFrame_ is always initialized.

> Otherwise seems like a good fix.
> 
> 
> Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> 
> > +
> > +       return 0;
> > +}
> > +
> >  int V4L2CameraProxy::vidioc_s_parm(V4L2CameraFile *file, struct v4l2_streamparm *arg)
> >  {
> >         LOG(V4L2Compat, Debug)
> > @@ -766,9 +805,25 @@ int V4L2CameraProxy::vidioc_s_parm(V4L2CameraFile *file, struct v4l2_streamparm
> >         if (!validateBufferType(arg->type))
> >                 return -EINVAL;
> >  
> > -       struct v4l2_fract *timeperframe = &arg->parm.capture.timeperframe;
> > -       utils::Duration frameDuration = 1.0s * timeperframe->numerator / timeperframe->denominator;
> > +       /*
> > +        * Store the frame duration if it is valid, otherwise keep the current
> > +        * value.
> > +        *
> > +        * \todo The provided value should be adjusted based on the camera
> > +        * capabilities.
> > +        */
> > +       if (arg->parm.capture.timeperframe.numerator &&
> > +           arg->parm.capture.timeperframe.denominator)
> > +               v4l2TimePerFrame_ = arg->parm.capture.timeperframe;
> >  
> > +       memset(&arg->parm, 0, sizeof(arg->parm));
> > +
> > +       arg->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
> > +       arg->parm.capture.timeperframe = v4l2TimePerFrame_;
> > +
> > +       /* Apply the frame duration. */
> > +       utils::Duration frameDuration = 1.0s * v4l2TimePerFrame_.numerator
> > +                                     / v4l2TimePerFrame_.denominator;
> >         int64_t uDuration = frameDuration.get<std::micro>();
> >         vcam_->controls().set(controls::FrameDurationLimits, { uDuration, uDuration });
> >  
> > @@ -795,6 +850,7 @@ const std::set<unsigned long> V4L2CameraProxy::supportedIoctls_ = {
> >         VIDIOC_EXPBUF,
> >         VIDIOC_STREAMON,
> >         VIDIOC_STREAMOFF,
> > +       VIDIOC_G_PARM,
> >         VIDIOC_S_PARM,
> >  };
> >  
> > @@ -883,6 +939,9 @@ int V4L2CameraProxy::ioctl(V4L2CameraFile *file, unsigned long longRequest, void
> >         case VIDIOC_STREAMOFF:
> >                 ret = vidioc_streamoff(file, static_cast<int *>(arg));
> >                 break;
> > +       case VIDIOC_G_PARM:
> > +               ret = vidioc_g_parm(file, static_cast<struct v4l2_streamparm *>(arg));
> > +               break;
> >         case VIDIOC_S_PARM:
> >                 ret = vidioc_s_parm(file, static_cast<struct v4l2_streamparm *>(arg));
> >                 break;
> > diff --git a/src/v4l2/v4l2_camera_proxy.h b/src/v4l2/v4l2_camera_proxy.h
> > index c957db5349cc..5aa352c36f6a 100644
> > --- a/src/v4l2/v4l2_camera_proxy.h
> > +++ b/src/v4l2/v4l2_camera_proxy.h
> > @@ -67,6 +67,7 @@ private:
> >         int vidioc_expbuf(V4L2CameraFile *file, struct v4l2_exportbuffer *arg);
> >         int vidioc_streamon(V4L2CameraFile *file, int *arg);
> >         int vidioc_streamoff(V4L2CameraFile *file, int *arg);
> > +       int vidioc_g_parm(V4L2CameraFile *file, struct v4l2_streamparm *arg);
> >         int vidioc_s_parm(V4L2CameraFile *file, struct v4l2_streamparm *arg);
> >  
> >         bool hasOwnership(V4L2CameraFile *file);
> > @@ -85,6 +86,7 @@ private:
> >  
> >         struct v4l2_capability capabilities_;
> >         struct v4l2_pix_format v4l2PixFormat_;
> > +       struct v4l2_fract v4l2TimePerFrame_;
> >  
> >         std::vector<struct v4l2_buffer> buffers_;
> >         std::map<void *, unsigned int> mmaps_;
> > 
> > base-commit: 58598f4dde9a3d4236ed52881da9b155443cbc50

-- 
Regards,

Laurent Pinchart