Hi Laurent,
On Fri, Sep 15, 2023 at 12:42:39PM +0300, Laurent Pinchart wrote:
> Hi Sakari,
>
> Thank you for the patch.
>
> On Fri, Sep 15, 2023 at 10:28:07AM +0300, Sakari Ailus wrote:
> > Enable runtime PM before registering the async sub-device as the ipu
> > bridge may try to resume the device immediately after the async sub-device
>
> I wouldn't mention ipu bridge there, as this driver is not specific to a
> particular CSI-2 receiver.
>
> > has been registered. If runtime PM is still disabled, this will fail.
> >
> > Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> > ---
> > drivers/media/i2c/ov2740.c | 14 ++++++++------
> > 1 file changed, 8 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/media/i2c/ov2740.c b/drivers/media/i2c/ov2740.c
> > index 41d4f85470fd..319dc00e47b4 100644
> > --- a/drivers/media/i2c/ov2740.c
> > +++ b/drivers/media/i2c/ov2740.c
> > @@ -1172,6 +1172,12 @@ static int ov2740_probe(struct i2c_client *client)
> > goto probe_error_v4l2_ctrl_handler_free;
> > }
> >
> > + /* Set the device's state to active if it's in D0 state. */
> > + if (full_power)
> > + pm_runtime_set_active(&client->dev);
>
> I wonder why we need this in drivers. If ACPI has powered the device on
> prior to calling probe(), couldn't it also set the PM runtime state
> accordingly ?
What happens here is that the ipu bridge creates a VCM device and it
resumes the related sensor before instantiating that device (see
ipu_bridge_instantiate_vcm_work()). However this may take place already
right after registering the async sub-device. Resuming the sensor will fail
if runtime PM isn't enabled.
I'll add something along these lines to the commit message.
>
> > + pm_runtime_enable(&client->dev);
> > + pm_runtime_idle(&client->dev);
> > +
>
> With the commit message fixed,
>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Thank you.
>
> > ret = v4l2_async_register_subdev_sensor(&ov2740->sd);
> > if (ret < 0) {
> > dev_err_probe(dev, ret, "failed to register V4L2 subdev\n");
> > @@ -1182,16 +1188,12 @@ static int ov2740_probe(struct i2c_client *client)
> > if (ret)
> > dev_warn(&client->dev, "register nvmem failed, ret %d\n", ret);
> >
> > - /* Set the device's state to active if it's in D0 state. */
> > - if (full_power)
> > - pm_runtime_set_active(&client->dev);
> > - pm_runtime_enable(&client->dev);
> > - pm_runtime_idle(&client->dev);
> > -
> > return 0;
> >
> > probe_error_media_entity_cleanup:
> > media_entity_cleanup(&ov2740->sd.entity);
> > + pm_runtime_disable(&client->dev);
> > + pm_runtime_set_suspended(&client->dev);
> >
> > probe_error_v4l2_ctrl_handler_free:
> > v4l2_ctrl_handler_free(ov2740->sd.ctrl_handler);
>
--
Regards,
Sakari Ailus
