Hi Wenyou, On Mon, Oct 09, 2017 at 01:49:44PM +0800, Yang, Wenyou wrote: > Hi Sakari, > > Sorry for late answer, because I was in vacation last week. > > On 2017/9/29 5:25, Sakari Ailus wrote: > > Hi Wenyou, > > > > On Thu, Sep 28, 2017 at 04:18:26PM +0800, Wenyou Yang wrote: > > > To meet the relationship, enable the HCLOCK and ispck during the > > > device probe, "isc_pck frequency is less than or equal to isc_ispck, > > > and isc_ispck is greater than or equal to HCLOCK." > > > Meanwhile, call the pm_runtime_enable() in the right place. > > > > > > Signed-off-by: Wenyou Yang <wenyou.y...@microchip.com> > > > --- > > > > > > Changes in v3: None > > > Changes in v2: None > > > > > > drivers/media/platform/atmel/atmel-isc.c | 31 > > > +++++++++++++++++++++++++------ > > > 1 file changed, 25 insertions(+), 6 deletions(-) > > > > > > diff --git a/drivers/media/platform/atmel/atmel-isc.c > > > b/drivers/media/platform/atmel/atmel-isc.c > > > index 0b15dc1a3a0b..f092c95587c1 100644 > > > --- a/drivers/media/platform/atmel/atmel-isc.c > > > +++ b/drivers/media/platform/atmel/atmel-isc.c > > > @@ -1594,6 +1594,7 @@ static int isc_async_complete(struct > > > v4l2_async_notifier *notifier) > > > struct isc_subdev_entity *sd_entity; > > > struct video_device *vdev = &isc->video_dev; > > > struct vb2_queue *q = &isc->vb2_vidq; > > > + struct device *dev = isc->dev; > > > int ret; > > > ret = v4l2_device_register_subdev_nodes(&isc->v4l2_dev); > > > @@ -1677,6 +1678,10 @@ static int isc_async_complete(struct > > > v4l2_async_notifier *notifier) > > > return ret; > > > } > > > + pm_runtime_set_active(dev); > > > + pm_runtime_enable(dev); > > > + pm_request_idle(dev); > > Remember that the driver's async complete function could never get called. > > > > What would be the reason to move it here? > The ISC provides the clock for the sensor, namely, it is the clock provider > for the external sensor. > So it keeps active to make the sensor probe successfully. > Otherwise, the sensor, such as 0v7670 fails to probe due to the failure to > clk_enable().
You'll still need to balance the get and put calls. complete callback is not necessarily called at all or could be called multiple times. Instead, you should probably do pm_runtime_get_sync() when the clock is enabled and put when it's disabled. -- Sakari Ailus e-mail: sakari.ai...@iki.fi
