[libcamera-devel] [PATCH v4 1/7] libcamera: delayed_controls: Add notion of priority write

Jean-Michel Hautbois jeanmichel.hautbois at ideasonboard.com
Tue Mar 9 10:54:41 CET 2021


Hi Naushir,

Thanks for the patch !

On 04/03/2021 09:17, Naushir Patuck wrote:
> If an exposure time change adjusts the vblanking limits, and we set both
> VBLANK and EXPOSURE controls through the VIDIOC_S_EXT_CTRLS ioctl, the
> latter may fail if the value is outside of the limits calculated by the
> old VBLANK value. This is a limitation in V4L2 and cannot be fixed by
> setting VBLANK before EXPOSURE in a single VIDIOC_S_EXT_CTRLS ioctl.
> 
> The workaround here is to have the DelayedControls object mark the
> VBLANK control as "priority write", which then write VBLANK separately
> from (and ahead of) any other controls. This way, the sensor driver will
> update the EXPOSURE control with new limits before the new values is
> presented, and will thus be seen as valid.
> 
> To support this, a new struct DelayedControls::ControlParams is used in
> the constructor to provide the control delay value as well as the
> priority write flag.
> 
> Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
> Tested-by: David Plowman <david.plowman at raspberrypi.com>
> Reviewed-by: Paul Elder <paul.elder at ideasonboard.com>
Tested-by: Jean-Michel Hautbois <jeanmichel.hautbois at ideasonboard.com>

> ---
>  include/libcamera/internal/delayed_controls.h |  9 +++-
>  src/libcamera/delayed_controls.cpp            | 54 +++++++++++++------
>  src/libcamera/pipeline/ipu3/ipu3.cpp          |  8 +--
>  .../pipeline/raspberrypi/raspberrypi.cpp      | 13 +++--
>  src/libcamera/pipeline/rkisp1/rkisp1.cpp      |  8 +--
>  test/delayed_contols.cpp                      | 20 +++----
>  6 files changed, 68 insertions(+), 44 deletions(-)
> 
> diff --git a/include/libcamera/internal/delayed_controls.h b/include/libcamera/internal/delayed_controls.h
> index dc447a882514..564d9f2e2440 100644
> --- a/include/libcamera/internal/delayed_controls.h
> +++ b/include/libcamera/internal/delayed_controls.h
> @@ -19,8 +19,13 @@ class V4L2Device;
>  class DelayedControls
>  {
>  public:
> +	struct ControlParams {
> +		unsigned int delay;
> +		bool priorityWrite;
> +	};
> +
>  	DelayedControls(V4L2Device *device,
> -			const std::unordered_map<uint32_t, unsigned int> &delays);
> +			const std::unordered_map<uint32_t, ControlParams> &controlParams);
>  
>  	void reset();
>  
> @@ -64,7 +69,7 @@ private:
>  
>  	V4L2Device *device_;
>  	/* \todo Evaluate if we should index on ControlId * or unsigned int */
> -	std::unordered_map<const ControlId *, unsigned int> delays_;
> +	std::unordered_map<const ControlId *, ControlParams> controlParams_;
>  	unsigned int maxDelay_;
>  
>  	bool running_;
> diff --git a/src/libcamera/delayed_controls.cpp b/src/libcamera/delayed_controls.cpp
> index ab1d40057c5f..3ed1dfebd035 100644
> --- a/src/libcamera/delayed_controls.cpp
> +++ b/src/libcamera/delayed_controls.cpp
> @@ -40,15 +40,19 @@ LOG_DEFINE_CATEGORY(DelayedControls)
>  /**
>   * \brief Construct a DelayedControls instance
>   * \param[in] device The V4L2 device the controls have to be applied to
> - * \param[in] delays Map of the numerical V4L2 control ids to their associated
> - * delays (in frames)
> + * \param[in] controlParams Map of the numerical V4L2 control ids to their
> + * associated control parameters.
>   *
> - * Only controls specified in \a delays are handled. If it's desired to mix
> - * delayed controls and controls that take effect immediately the immediate
> - * controls must be listed in the \a delays map with a delay value of 0.
> + * The control parameters comprise of delays (in frames) and a priority write
> + * flag. If this flag is set, the relevant control is written separately from,
> + * ahead of the reset of the batched controls.
> + *
> + * Only controls specified in \a controlParams are handled. If it's desired to
> + * mix delayed controls and controls that take effect immediately the immediate
> + * controls must be listed in the \a controlParams map with a delay value of 0.
>   */
>  DelayedControls::DelayedControls(V4L2Device *device,
> -				 const std::unordered_map<uint32_t, unsigned int> &delays)
> +				 const std::unordered_map<uint32_t, ControlParams> &controlParams)
>  	: device_(device), maxDelay_(0)
>  {
>  	const ControlInfoMap &controls = device_->controls();
> @@ -57,12 +61,12 @@ DelayedControls::DelayedControls(V4L2Device *device,
>  	 * Create a map of control ids to delays for controls exposed by the
>  	 * device.
>  	 */
> -	for (auto const &delay : delays) {
> -		auto it = controls.find(delay.first);
> +	for (auto const &param : controlParams) {
> +		auto it = controls.find(param.first);
>  		if (it == controls.end()) {
>  			LOG(DelayedControls, Error)
>  				<< "Delay request for control id "
> -				<< utils::hex(delay.first)
> +				<< utils::hex(param.first)
>  				<< " but control is not exposed by device "
>  				<< device_->deviceNode();
>  			continue;
> @@ -70,13 +74,14 @@ DelayedControls::DelayedControls(V4L2Device *device,
>  
>  		const ControlId *id = it->first;
>  
> -		delays_[id] = delay.second;
> +		controlParams_[id] = param.second;
>  
>  		LOG(DelayedControls, Debug)
> -			<< "Set a delay of " << delays_[id]
> +			<< "Set a delay of " << controlParams_[id].delay
> +			<< " and priority write flag " << controlParams_[id].priorityWrite
>  			<< " for " << id->name();
>  
> -		maxDelay_ = std::max(maxDelay_, delays_[id]);
> +		maxDelay_ = std::max(maxDelay_, controlParams_[id].delay);
>  	}
>  
>  	reset();
> @@ -97,8 +102,8 @@ void DelayedControls::reset()
>  
>  	/* Retrieve control as reported by the device. */
>  	std::vector<uint32_t> ids;
> -	for (auto const &delay : delays_)
> -		ids.push_back(delay.first->id());
> +	for (auto const &param : controlParams_)
> +		ids.push_back(param.first->id());
>  
>  	ControlList controls = device_->getControls(ids);
>  
> @@ -140,7 +145,7 @@ bool DelayedControls::push(const ControlList &controls)
>  
>  		const ControlId *id = it->second;
>  
> -		if (delays_.find(id) == delays_.end())
> +		if (controlParams_.find(id) == controlParams_.end())
>  			return false;
>  
>  		Info &info = values_[id][queueCount_];
> @@ -220,12 +225,27 @@ void DelayedControls::applyControls(uint32_t sequence)
>  	ControlList out(device_->controls());
>  	for (const auto &ctrl : values_) {
>  		const ControlId *id = ctrl.first;
> -		unsigned int delayDiff = maxDelay_ - delays_[id];
> +		unsigned int delayDiff = maxDelay_ - controlParams_[id].delay;
>  		unsigned int index = std::max<int>(0, writeCount_ - delayDiff);
>  		const Info &info = ctrl.second[index];
>  
>  		if (info.updated) {
> -			out.set(id->id(), info);
> +			if (controlParams_[id].priorityWrite) {
> +				/*
> +				 * This control must be written now, it could
> +				 * affect validity of the other controls.
> +				 */
> +				ControlList priority(device_->controls());
> +				priority.set(id->id(), info);
> +				device_->setControls(&priority);
> +			} else {
> +				/*
> +				 * Batch up the list of controls and write them
> +				 * at the end of the function.
> +				 */
> +				out.set(id->id(), info);
> +			}
> +
>  			LOG(DelayedControls, Debug)
>  				<< "Setting " << id->name()
>  				<< " to " << info.toString()
> diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
> index 3e6b88af4188..ac92f066a07e 100644
> --- a/src/libcamera/pipeline/ipu3/ipu3.cpp
> +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
> @@ -963,14 +963,14 @@ int PipelineHandlerIPU3::registerCameras()
>  		 * a sensor database. For now use generic values taken from
>  		 * the Raspberry Pi and listed as 'generic values'.
>  		 */
> -		std::unordered_map<uint32_t, unsigned int> delays = {
> -			{ V4L2_CID_ANALOGUE_GAIN, 1 },
> -			{ V4L2_CID_EXPOSURE, 2 },
> +		std::unordered_map<uint32_t, DelayedControls::ControlParams> params = {
> +			{ V4L2_CID_ANALOGUE_GAIN, { 1, false } },
> +			{ V4L2_CID_EXPOSURE, { 2, false } },
>  		};
>  
>  		data->delayedCtrls_ =
>  			std::make_unique<DelayedControls>(cio2->sensor()->device(),
> -							  delays);
> +							  params);
>  		data->cio2_.frameStart().connect(data->delayedCtrls_.get(),
>  						 &DelayedControls::applyControls);
>  
> diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> index a60415d93705..ba74ace183db 100644
> --- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> +++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
> @@ -1244,16 +1244,15 @@ int RPiCameraData::configureIPA(const CameraConfiguration *config)
>  	if (result.params & ipa::RPi::ConfigSensorParams) {
>  		/*
>  		 * Setup our delayed control writer with the sensor default
> -		 * gain and exposure delays.
> +		 * gain and exposure delays. Mark VBLANK for priority write.
>  		 */
> -		std::unordered_map<uint32_t, unsigned int> delays = {
> -			{ V4L2_CID_ANALOGUE_GAIN, result.sensorConfig.gainDelay },
> -			{ V4L2_CID_EXPOSURE, result.sensorConfig.exposureDelay },
> -			{ V4L2_CID_VBLANK, result.sensorConfig.vblank }
> +		std::unordered_map<uint32_t, DelayedControls::ControlParams> params = {
> +			{ V4L2_CID_ANALOGUE_GAIN, { result.sensorConfig.gainDelay, false } },
> +			{ V4L2_CID_EXPOSURE, { result.sensorConfig.exposureDelay, false } },
> +			{ V4L2_CID_VBLANK, { result.sensorConfig.vblank, true } }
>  		};
>  
> -		delayedCtrls_ = std::make_unique<DelayedControls>(unicam_[Unicam::Image].dev(), delays);
> -
> +		delayedCtrls_ = std::make_unique<DelayedControls>(unicam_[Unicam::Image].dev(), params);
>  		sensorMetadata_ = result.sensorConfig.sensorMetadata;
>  	}
>  
> diff --git a/src/libcamera/pipeline/rkisp1/rkisp1.cpp b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> index a794501a9c8d..17c0f9751cd3 100644
> --- a/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> +++ b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> @@ -938,14 +938,14 @@ int PipelineHandlerRkISP1::createCamera(MediaEntity *sensor)
>  	 * a sensor database. For now use generic values taken from
>  	 * the Raspberry Pi and listed as generic values.
>  	 */
> -	std::unordered_map<uint32_t, unsigned int> delays = {
> -		{ V4L2_CID_ANALOGUE_GAIN, 1 },
> -		{ V4L2_CID_EXPOSURE, 2 },
> +	std::unordered_map<uint32_t, DelayedControls::ControlParams> params = {
> +		{ V4L2_CID_ANALOGUE_GAIN, { 1, false } },
> +		{ V4L2_CID_EXPOSURE, { 2, false } },
>  	};
>  
>  	data->delayedCtrls_ =
>  		std::make_unique<DelayedControls>(data->sensor_->device(),
> -						  delays);
> +						  params);
>  	isp_->frameStart.connect(data->delayedCtrls_.get(),
>  				 &DelayedControls::applyControls);
>  
> diff --git a/test/delayed_contols.cpp b/test/delayed_contols.cpp
> index 50169b12e566..3855eb18ecd4 100644
> --- a/test/delayed_contols.cpp
> +++ b/test/delayed_contols.cpp
> @@ -72,8 +72,8 @@ protected:
>  
>  	int singleControlNoDelay()
>  	{
> -		std::unordered_map<uint32_t, unsigned int> delays = {
> -			{ V4L2_CID_BRIGHTNESS, 0 },
> +		std::unordered_map<uint32_t, DelayedControls::ControlParams> delays = {
> +			{ V4L2_CID_BRIGHTNESS, { 0, false } },
>  		};
>  		std::unique_ptr<DelayedControls> delayed =
>  			std::make_unique<DelayedControls>(dev_.get(), delays);
> @@ -109,8 +109,8 @@ protected:
>  
>  	int singleControlWithDelay()
>  	{
> -		std::unordered_map<uint32_t, unsigned int> delays = {
> -			{ V4L2_CID_BRIGHTNESS, 1 },
> +		std::unordered_map<uint32_t, DelayedControls::ControlParams> delays = {
> +			{ V4L2_CID_BRIGHTNESS, { 1, false } },
>  		};
>  		std::unique_ptr<DelayedControls> delayed =
>  			std::make_unique<DelayedControls>(dev_.get(), delays);
> @@ -150,9 +150,9 @@ protected:
>  
>  	int dualControlsWithDelay(uint32_t startOffset)
>  	{
> -		std::unordered_map<uint32_t, unsigned int> delays = {
> -			{ V4L2_CID_BRIGHTNESS, 1 },
> -			{ V4L2_CID_CONTRAST, 2 },
> +		std::unordered_map<uint32_t, DelayedControls::ControlParams> delays = {
> +			{ V4L2_CID_BRIGHTNESS, { 1, false } },
> +			{ V4L2_CID_CONTRAST, { 2, false } },
>  		};
>  		std::unique_ptr<DelayedControls> delayed =
>  			std::make_unique<DelayedControls>(dev_.get(), delays);
> @@ -197,9 +197,9 @@ protected:
>  
>  	int dualControlsMultiQueue()
>  	{
> -		std::unordered_map<uint32_t, unsigned int> delays = {
> -			{ V4L2_CID_BRIGHTNESS, 1 },
> -			{ V4L2_CID_CONTRAST, 2 },
> +		std::unordered_map<uint32_t, DelayedControls::ControlParams> delays = {
> +			{ V4L2_CID_BRIGHTNESS, { 1, false } },
> +			{ V4L2_CID_CONTRAST, { 2, false } }
>  		};
>  		std::unique_ptr<DelayedControls> delayed =
>  			std::make_unique<DelayedControls>(dev_.get(), delays);
> 


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