Hi Jacopo,
Thanks for your comments.
>
> Hi Changhuang
>
> On Wed, Jul 17, 2024 at 08:28:34PM GMT, Changhuang Liang wrote:
> > This patch implements system suspend and system resume operation for
> > StarFive Camera Subsystem. It supports hibernation during streaming
> > and restarts streaming at system resume time.
> >
> > Signed-off-by: Changhuang Liang <changhuang.liang@xxxxxxxxxxxxxxxx>
> > ---
> > .../staging/media/starfive/camss/stf-camss.c | 49
> > +++++++++++++++++++
> > 1 file changed, 49 insertions(+)
> >
> > diff --git a/drivers/staging/media/starfive/camss/stf-camss.c
> > b/drivers/staging/media/starfive/camss/stf-camss.c
> > index fecd3e67c7a1..8dcd35aef69d 100644
> > --- a/drivers/staging/media/starfive/camss/stf-camss.c
> > +++ b/drivers/staging/media/starfive/camss/stf-camss.c
> > @@ -416,10 +416,59 @@ static int __maybe_unused
> stfcamss_runtime_resume(struct device *dev)
> > return 0;
> > }
> >
> > +static int __maybe_unused stfcamss_suspend(struct device *dev) {
> > + struct stfcamss *stfcamss = dev_get_drvdata(dev);
> > + struct stfcamss_video *video;
>
> Can be declared inside the for loop
>
> > + unsigned int i;
> > +
> > + for (i = 0; i < STF_CAPTURE_NUM; ++i) {
>
> Likewise, if you like it, you can
>
> for (unsigned int i...
>
> > + video = &stfcamss->captures[i].video;
> > + if (video->vb2_q.streaming) {
> > + video->ops->stop_streaming(video);
> > + video->ops->flush_buffers(video, VB2_BUF_STATE_ERROR);
> > + }
> > + }
> > +
> > + return pm_runtime_force_suspend(dev); }
> > +
> > +static int __maybe_unused stfcamss_resume(struct device *dev) {
> > + struct stfcamss *stfcamss = dev_get_drvdata(dev);
> > + struct stf_isp_dev *isp_dev = &stfcamss->isp_dev;
> > + struct v4l2_subdev_state *sd_state;
> > + struct stfcamss_video *video;
> > + unsigned int i;
>
> same here
>
> > + int ret;
> > +
> > + ret = pm_runtime_force_resume(dev);
> > + if (ret < 0) {
> > + dev_err(dev, "Failed to resume\n");
> > + return ret;
> > + }
> > +
> > + sd_state = v4l2_subdev_lock_and_get_active_state(&isp_dev->subdev);
> > +
> > + if (isp_dev->streaming)
> > + stf_isp_stream_on(isp_dev, sd_state);
>
> I was wondering if you shouldn't propagate start_streaming along the whole
> pipline, but I presume the connected subdevs have to handle resuming
> streaming after a system resume themselves ?
>
Currently our Camera subsystem contains ISP subdev , capture_raw video device, and capture_yuv
video device. So you can see only one system PM hook can be used by them.
>
> > +
> > + v4l2_subdev_unlock_state(sd_state);
> > +
> > + for (i = 0; i < STF_CAPTURE_NUM; ++i) {
> > + video = &stfcamss->captures[i].video;
> > + if (video->vb2_q.streaming)
> > + video->ops->start_streaming(video);
>
> You can use vb2_is_streaming() maybe.
> If the queue is streaming, do you need to keep a 'streaming' flag for the isp ?
> Probably yes, as the ISP subdev is used by several video nodes ?
>
I set the "streaming" flag in PATCH 4, so it does not affect that even if several video
nodes use it.
Regards,
Changhuang
