Re: [PATCH 2/4] media: imx: imx-mipi-csis: Drop unneeded system PM implementation

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Jacopo,

On Fri, Mar 11, 2022 at 05:53:25PM +0100, Jacopo Mondi wrote:
> Hi Laurent,
> 
>    the commit title makes me think runtime_pm has been dropped
> 
> I would
> 
> media: imx: imx-mipi-csis: Drop manual PM tracking

I wrote "system PM" specifically to avoid implying runtime PM was
dropped, but it seems it's not enough ? :-) I can change the subject,
but I find "manual PM tracking" not very descriptive of what the patch
does.

> On Fri, Mar 11, 2022 at 03:55:33PM +0200, Laurent Pinchart wrote:
> > There's no need to implement system suspend/resume manually, as video
> > pipelines are supposed to be suspended in a controlled and ordered
> > manner by the data sink driver at system suspend time (and similarly at
> > resume time). Drop the system suspend/resume handlers.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
> >  drivers/media/platform/imx/imx-mipi-csis.c | 48 +++-------------------
> >  1 file changed, 5 insertions(+), 43 deletions(-)
> >
> > diff --git a/drivers/media/platform/imx/imx-mipi-csis.c b/drivers/media/platform/imx/imx-mipi-csis.c
> > index 6e06d19c1334..3bdfe05a6c54 100644
> > --- a/drivers/media/platform/imx/imx-mipi-csis.c
> > +++ b/drivers/media/platform/imx/imx-mipi-csis.c
> > @@ -250,8 +250,6 @@
> >
> >  enum {
> >  	ST_POWERED	= 1,
> > -	ST_STREAMING	= 2,
> > -	ST_SUSPENDED	= 4,
> >  };
> 
> I see csis->state be dropped in the next patches so
> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
> 
> >  struct mipi_csis_event {
> > @@ -954,24 +952,17 @@ static int mipi_csis_s_stream(struct v4l2_subdev *sd, int enable)
> >  	mutex_lock(&csis->lock);
> >
> >  	if (enable) {
> > -		if (csis->state & ST_SUSPENDED) {
> > -			ret = -EBUSY;
> > -			goto unlock;
> > -		}
> > -
> >  		mipi_csis_start_stream(csis);
> >  		ret = v4l2_subdev_call(csis->src_sd, video, s_stream, 1);
> >  		if (ret < 0)
> >  			goto unlock;
> >
> >  		mipi_csis_log_counters(csis, true);
> > -
> > -		csis->state |= ST_STREAMING;
> >  	} else {
> >  		v4l2_subdev_call(csis->src_sd, video, s_stream, 0);
> >
> >  		mipi_csis_stop_stream(csis);
> > -		csis->state &= ~ST_STREAMING;
> > +
> >  		if (csis->debug.enable)
> >  			mipi_csis_log_counters(csis, true);
> >  	}
> > @@ -1356,7 +1347,7 @@ static int mipi_csis_async_register(struct mipi_csis_device *csis)
> >   * Suspend/resume
> >   */
> >
> > -static int mipi_csis_pm_suspend(struct device *dev, bool runtime)
> > +static int __maybe_unused mipi_csis_runtime_suspend(struct device *dev)
> >  {
> >  	struct v4l2_subdev *sd = dev_get_drvdata(dev);
> >  	struct mipi_csis_device *csis = sd_to_mipi_csis_device(sd);
> > @@ -1370,8 +1361,6 @@ static int mipi_csis_pm_suspend(struct device *dev, bool runtime)
> >  			goto unlock;
> >  		mipi_csis_clk_disable(csis);
> >  		csis->state &= ~ST_POWERED;
> > -		if (!runtime)
> > -			csis->state |= ST_SUSPENDED;
> >  	}
> >
> >  unlock:
> > @@ -1380,15 +1369,13 @@ static int mipi_csis_pm_suspend(struct device *dev, bool runtime)
> >  	return ret ? -EAGAIN : 0;
> >  }
> >
> > -static int mipi_csis_pm_resume(struct device *dev, bool runtime)
> > +static int __maybe_unused mipi_csis_runtime_resume(struct device *dev)
> >  {
> >  	struct v4l2_subdev *sd = dev_get_drvdata(dev);
> >  	struct mipi_csis_device *csis = sd_to_mipi_csis_device(sd);
> >  	int ret = 0;
> >
> >  	mutex_lock(&csis->lock);
> > -	if (!runtime && !(csis->state & ST_SUSPENDED))
> > -		goto unlock;
> >
> >  	if (!(csis->state & ST_POWERED)) {
> >  		ret = mipi_csis_phy_enable(csis);
> > @@ -1398,10 +1385,6 @@ static int mipi_csis_pm_resume(struct device *dev, bool runtime)
> >  		csis->state |= ST_POWERED;
> >  		mipi_csis_clk_enable(csis);
> >  	}
> > -	if (csis->state & ST_STREAMING)
> > -		mipi_csis_start_stream(csis);
> > -
> > -	csis->state &= ~ST_SUSPENDED;
> >
> >  unlock:
> >  	mutex_unlock(&csis->lock);
> > @@ -1409,30 +1392,9 @@ static int mipi_csis_pm_resume(struct device *dev, bool runtime)
> >  	return ret ? -EAGAIN : 0;
> >  }
> >
> > -static int __maybe_unused mipi_csis_suspend(struct device *dev)
> > -{
> > -	return mipi_csis_pm_suspend(dev, false);
> > -}
> > -
> > -static int __maybe_unused mipi_csis_resume(struct device *dev)
> > -{
> > -	return mipi_csis_pm_resume(dev, false);
> > -}
> > -
> > -static int __maybe_unused mipi_csis_runtime_suspend(struct device *dev)
> > -{
> > -	return mipi_csis_pm_suspend(dev, true);
> > -}
> > -
> > -static int __maybe_unused mipi_csis_runtime_resume(struct device *dev)
> > -{
> > -	return mipi_csis_pm_resume(dev, true);
> > -}
> > -
> >  static const struct dev_pm_ops mipi_csis_pm_ops = {
> >  	SET_RUNTIME_PM_OPS(mipi_csis_runtime_suspend, mipi_csis_runtime_resume,
> >  			   NULL)
> > -	SET_SYSTEM_SLEEP_PM_OPS(mipi_csis_suspend, mipi_csis_resume)
> >  };
> >
> >  /* -----------------------------------------------------------------------------
> > @@ -1557,7 +1519,7 @@ static int mipi_csis_probe(struct platform_device *pdev)
> >  	/* Enable runtime PM. */
> >  	pm_runtime_enable(dev);
> >  	if (!pm_runtime_enabled(dev)) {
> > -		ret = mipi_csis_pm_resume(dev, true);
> > +		ret = mipi_csis_runtime_resume(dev);
> >  		if (ret < 0)
> >  			goto unregister_all;
> >  	}
> > @@ -1592,7 +1554,7 @@ static int mipi_csis_remove(struct platform_device *pdev)
> >  	v4l2_async_unregister_subdev(&csis->sd);
> >
> >  	pm_runtime_disable(&pdev->dev);
> > -	mipi_csis_pm_suspend(&pdev->dev, true);
> > +	mipi_csis_runtime_suspend(&pdev->dev);
> >  	mipi_csis_clk_disable(csis);
> >  	media_entity_cleanup(&csis->sd.entity);
> >  	mutex_destroy(&csis->lock);

-- 
Regards,

Laurent Pinchart