[PATCH v2] libcamera: camera_sensor: Cache pixel rate

[Paul Elder]

On Tue, Jan 23, 2024 at 11:21:55AM +0530, Umang Jain wrote:
> Hi Paul
> 
> On 1/22/24 5:43 PM, Paul Elder wrote:
> > Cache the pixel rate at set format time instead of fetching it from the
> > v4l2 subdev every time it's needed.
> > 
> > It needs to be cached at set format time as opposed to initialization
> > time as some sensor drives (eg. imx708) change the pixel rate depending
> > on the mode.
> > 
> > Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>
> > 
> > ---
> > Changes in v2:
> > - Cache the pixel rate at set format time instead of at initialization
> >    time
> > ---
> >   include/libcamera/internal/camera_sensor.h | 2 ++
> >   src/libcamera/camera_sensor.cpp            | 8 +++++++-
> >   2 files changed, 9 insertions(+), 1 deletion(-)
> > 
> > diff --git a/include/libcamera/internal/camera_sensor.h b/include/libcamera/internal/camera_sensor.h
> > index 60a8b106d..da3bf12b3 100644
> > --- a/include/libcamera/internal/camera_sensor.h
> > +++ b/include/libcamera/internal/camera_sensor.h
> > @@ -105,6 +105,8 @@ private:
> >   	std::string model_;
> >   	std::string id_;
> > +	uint64_t pixelRate_;
> > +
> >   	V4L2Subdevice::Formats formats_;
> >   	std::vector<unsigned int> mbusCodes_;
> >   	std::vector<Size> sizes_;
> > diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp
> > index 0ef78d9c8..127610321 100644
> > --- a/src/libcamera/camera_sensor.cpp
> > +++ b/src/libcamera/camera_sensor.cpp
> > @@ -515,6 +515,9 @@ int CameraSensor::initProperties()
> >   		properties_.set(properties::draft::ColorFilterArrangement, cfa);
> >   	}
> > +	ControlList ctrls = subdev_->getControls({ V4L2_CID_PIXEL_RATE });
> > +	pixelRate_ = ctrls.get(V4L2_CID_PIXEL_RATE).get<int64_t>();
> > +
> 
> Do we have to cache it at two places? One initProperties() and other in
> setFormat() ?
> 
> In the change log, you have used ' instead of '  so I am a bit confused..

Oops. Yeah we need to cache it in both places.


Paul

> >   	return 0;
> >   }
> > @@ -814,6 +817,9 @@ int CameraSensor::setFormat(V4L2SubdeviceFormat *format, Transform transform)
> >   	if (ret)
> >   		return ret;
> > +	ControlList ctrls = subdev_->getControls({ V4L2_CID_PIXEL_RATE });
> > +	pixelRate_ = ctrls.get(V4L2_CID_PIXEL_RATE).get<int64_t>();
> > +
> >   	updateControlInfo();
> >   	return 0;
> >   }
> > @@ -1080,7 +1086,7 @@ int CameraSensor::sensorInfo(IPACameraSensorInfo *info) const
> >   		return -EINVAL;
> >   	}
> > -	info->pixelRate = ctrls.get(V4L2_CID_PIXEL_RATE).get<int64_t>();
> > +	info->pixelRate = pixelRate_;
> >   	const ControlInfo hblank = ctrls.infoMap()->at(V4L2_CID_HBLANK);
> >   	info->minLineLength = info->outputSize.width + hblank.min().get<int32_t>();
>