[libcamera-devel] [PATCH v1] v4l2_videodevice: Disable the watchdog timer when no buffers are queued

[Kieran Bingham]

Quoting Naushir Patuck via libcamera-devel (2022-05-10 08:58:39)
> Hi,
> 
> On Thu, 5 May 2022 at 09:48, Naushir Patuck <naush at raspberrypi.com> wrote:
> 
> > Only enable/reset the watchdog timer when there are buffers queued in the
> > V4L2
> > device. Otherwise, we may trigger spurious warnings when the watchdog
> > times out
> > even if there are no buffers queued in the device.
> >
> > Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
> >
> 
> Gentle ping.  This needs one more R-B tag to get merged.

David, can we upgrade your Tested-by: to a Reviewed-by: ? (Or maybe TB
is sufficient?)


> 
> Regards,
> Naush
> 
> 
> > ---
> >  src/libcamera/v4l2_videodevice.cpp | 22 +++++++++++++++-------
> >  1 file changed, 15 insertions(+), 7 deletions(-)
> >
> > diff --git a/src/libcamera/v4l2_videodevice.cpp
> > b/src/libcamera/v4l2_videodevice.cpp
> > index 5b4637b1a39e..430715afd554 100644
> > --- a/src/libcamera/v4l2_videodevice.cpp
> > +++ b/src/libcamera/v4l2_videodevice.cpp
> > @@ -1662,8 +1662,11 @@ int V4L2VideoDevice::queueBuffer(FrameBuffer
> > *buffer)
> >                 return ret;
> >         }
> >
> > -       if (queuedBuffers_.empty())
> > +       if (queuedBuffers_.empty()) {
> >                 fdBufferNotifier_->setEnabled(true);
> > +               if (watchdogDuration_)
> > +
> >  watchdog_.start(std::chrono::duration_cast<std::chrono::milliseconds>(watchdogDuration_));
> > +       }
> >
> >         queuedBuffers_[buf.index] = buffer;
> >
> > @@ -1742,16 +1745,21 @@ 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;
> >         queuedBuffers_.erase(it);
> >
> > -       if (queuedBuffers_.empty())
> > +       if (queuedBuffers_.empty()) {
> >                 fdBufferNotifier_->setEnabled(false);
> > +               watchdog_.stop();
> > +       } else if (watchdogDuration_) {
> > +               /*
> > +                * Restart the watchdog timer if there are buffers still
> > queued
> > +                * in the device.
> > +                */
> > +
> >  watchdog_.start(std::chrono::duration_cast<std::chrono::milliseconds>(watchdogDuration_));
> > +       }
> >
> >         buffer->metadata_.status = buf.flags & V4L2_BUF_FLAG_ERROR
> >                                  ? FrameMetadata::FrameError
> > @@ -1847,7 +1855,7 @@ int V4L2VideoDevice::streamOn()
> >         }
> >
> >         state_ = State::Streaming;
> > -       if (watchdogDuration_.count())
> > +       if (watchdogDuration_ && !queuedBuffers_.empty())
> >
> > watchdog_.start(std::chrono::duration_cast<std::chrono::milliseconds>(watchdogDuration_));
> >
> >         return 0;
> > @@ -1924,7 +1932,7 @@ void
> > V4L2VideoDevice::setDequeueTimeout(utils::Duration timeout)
> >         watchdogDuration_ = timeout;
> >
> >         watchdog_.stop();
> > -       if (watchdogDuration_.count() && state_ == State::Streaming)
> > +       if (watchdogDuration_ && state_ == State::Streaming &&
> > !queuedBuffers_.empty())
> >
> > watchdog_.start(std::chrono::duration_cast<std::chrono::milliseconds>(timeout));
> >  }
> >
> > --
> > 2.25.1
> >
> >