libcamera: v4l2_videodevice: Add a dequeue timer

Add a timer that gets reset on every buffer dequeue event. If the timeout
expires, optionally call a slot in the pipeline handler to handle this
condition. This may be useful in detecting and handling stalls in either the
hardware or device driver.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
This commit is contained in:
Naushir Patuck 2022-04-06 13:35:52 +01:00 committed by Laurent Pinchart
parent 226792a141
commit 16f3d2de50
2 changed files with 63 additions and 0 deletions

View file

@ -20,7 +20,9 @@
#include <libcamera/base/class.h>
#include <libcamera/base/log.h>
#include <libcamera/base/signal.h>
#include <libcamera/base/timer.h>
#include <libcamera/base/unique_fd.h>
#include <libcamera/base/utils.h>
#include <libcamera/color_space.h>
#include <libcamera/framebuffer.h>
@ -217,6 +219,9 @@ public:
int streamOn();
int streamOff();
void setDequeueTimeout(utils::Duration timeout);
Signal<> dequeueTimeout;
static std::unique_ptr<V4L2VideoDevice>
fromEntityName(const MediaDevice *media, const std::string &entity);
@ -253,6 +258,8 @@ private:
void bufferAvailable();
FrameBuffer *dequeueBuffer();
void watchdogExpired();
V4L2Capability caps_;
V4L2DeviceFormat format_;
const PixelFormatInfo *formatInfo_;
@ -266,6 +273,9 @@ private:
EventNotifier *fdBufferNotifier_;
State state_;
Timer watchdog_;
utils::Duration watchdogDuration_;
};
class V4L2M2MDevice

View file

@ -539,6 +539,7 @@ V4L2VideoDevice::V4L2VideoDevice(const std::string &deviceNode)
V4L2VideoDevice::V4L2VideoDevice(const MediaEntity *entity)
: V4L2VideoDevice(entity->deviceNode())
{
watchdog_.timeout.connect(this, &V4L2VideoDevice::watchdogExpired);
}
V4L2VideoDevice::~V4L2VideoDevice()
@ -1726,6 +1727,9 @@ FrameBuffer *V4L2VideoDevice::dequeueBuffer()
return nullptr;
}
if (watchdogDuration_.count())
watchdog_.start(std::chrono::duration_cast<std::chrono::milliseconds>(watchdogDuration_));
cache_->put(buf.index);
FrameBuffer *buffer = it->second;
@ -1828,6 +1832,8 @@ int V4L2VideoDevice::streamOn()
}
state_ = State::Streaming;
if (watchdogDuration_.count())
watchdog_.start(std::chrono::duration_cast<std::chrono::milliseconds>(watchdogDuration_));
return 0;
}
@ -1852,6 +1858,9 @@ int V4L2VideoDevice::streamOff()
if (state_ != State::Streaming && queuedBuffers_.empty())
return 0;
if (watchdogDuration_.count())
watchdog_.stop();
ret = ioctl(VIDIOC_STREAMOFF, &bufferType_);
if (ret < 0) {
LOG(V4L2, Error)
@ -1879,6 +1888,50 @@ int V4L2VideoDevice::streamOff()
return 0;
}
/**
* \brief Set the dequeue timeout value
* \param[in] timeout The timeout value to be used
*
* Sets a timeout value, given by \a timeout, that will be used by a watchdog
* timer to ensure buffer dequeue events are periodically occurring when the
* device is streaming. The watchdog timer is only active when the device is
* streaming, so it is not necessary to disable it when the device stops
* streaming. The timeout value can be safely updated at any time.
*
* If the timer expires, the \ref V4L2VideoDevice::dequeueTimeout signal is
* emitted. This can typically be used by pipeline handlers to be notified of
* stalled devices.
*
* Set \a timeout to 0 to disable the watchdog timer.
*/
void V4L2VideoDevice::setDequeueTimeout(utils::Duration timeout)
{
watchdogDuration_ = timeout;
watchdog_.stop();
if (watchdogDuration_.count() && state_ == State::Streaming)
watchdog_.start(std::chrono::duration_cast<std::chrono::milliseconds>(timeout));
}
/**
* \var V4L2VideoDevice::dequeueTimeout
* \brief A Signal emitted when the dequeue watchdog timer expires
*/
/**
* \brief Slot to handle an expired dequeue timer
*
* When this slot is called, the time between successive dequeue events is over
* the required timeout. Emit the \ref V4L2VideoDevice::dequeueTimeout signal.
*/
void V4L2VideoDevice::watchdogExpired()
{
LOG(V4L2, Warning)
<< "Dequeue timer of " << watchdogDuration_ << " has expired!";
dequeueTimeout.emit();
}
/**
* \brief Create a new video device instance from \a entity in media device
* \a media