Hi, Jai,
> Hi Changhuang,
>
> On Jun 28, 2024 at 08:45:06 +0000, Changhuang Liang wrote:
> > Hi Tomi,
> >
> > [...]
> > > > +static int csi2rx_suspend(struct device *dev) {
> > > > + struct csi2rx_priv *csi2rx = dev_get_drvdata(dev);
> > > > +
> > > > + mutex_lock(&csi2rx->lock);
> > > > + if (csi2rx->count)
> > > > + csi2rx_stop(csi2rx);
> > > > + mutex_unlock(&csi2rx->lock);
> > > > +
> > > > + return 0;
> > > > +}
> > > > +
> > > > +static int csi2rx_resume(struct device *dev) {
> > > > + struct csi2rx_priv *csi2rx = dev_get_drvdata(dev);
> > > > +
> > > > + mutex_lock(&csi2rx->lock);
> > > > + if (csi2rx->count)
> > > > + csi2rx_start(csi2rx);
> > > > + mutex_unlock(&csi2rx->lock);
> > > > + return 0;
> > > > +}
> > > > +
> > >
> > > I don't think this looks correct. Afaik the runtime suspend/resume
> > > is not called on system suspend/resume. You could change the
> > > SET_RUNTIME_PM_OPS to use the same callbacks for runtime and
> system
> > > suspend, but I think that's a bad idea. Runtime suspend is not
> > > supposed to turn off the streaming. The driver is supposed to turn
> > > off the streaming, then call runtime_put, which would result in runtime
> suspend callback getting called.
> > >
> >
> > I implemented system suspend/resume based on this patch, I feel good
> about it.
> >
> > https://lore.kernel.org/all/20240326031237.25331-1-changhuang.liang@st
> > arfivetech.com/
>
> Thanks for carrying this patch in your series.
>
> I think Tomi's point still holds - only the system suspend hook should try to
> stop/start the CSI2RX device.
>
> Runtime PM hooks are usually only called when there are no users, so no
> active streams.
>
OK, I will modify this in my series.
Regards,
Changhuang
