Hi Mauro,
On Mon, Apr 26, 2021 at 04:01:51PM +0200, Mauro Carvalho Chehab wrote:
> Em Sun, 25 Apr 2021 21:55:25 +0300
> Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> escreveu:
>
> > Hi Mauro,
> >
> > Thanks for the patch.
> >
> > On Sat, Apr 24, 2021 at 08:44:35AM +0200, Mauro Carvalho Chehab wrote:
> > > Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
> > > added pm_runtime_resume_and_get() in order to automatically handle
> > > dev->power.usage_count decrement on errors.
> > >
> > > Use the new API, in order to cleanup the error check logic.
> > >
> > > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
> > > ---
> > > drivers/media/i2c/ccs/ccs-core.c | 11 +++++------
> > > 1 file changed, 5 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/drivers/media/i2c/ccs/ccs-core.c b/drivers/media/i2c/ccs/ccs-core.c
> > > index 9dc3f45da3dc..1441ddcc9b35 100644
> > > --- a/drivers/media/i2c/ccs/ccs-core.c
> > > +++ b/drivers/media/i2c/ccs/ccs-core.c
> > > @@ -1880,12 +1880,11 @@ static int ccs_pm_get_init(struct ccs_sensor *sensor)
> > > struct i2c_client *client = v4l2_get_subdevdata(&sensor->src->sd);
> > > int rval;
> > >
> > > - rval = pm_runtime_get_sync(&client->dev);
> > > - if (rval < 0) {
> > > - pm_runtime_put_noidle(&client->dev);
> > > -
> > > + rval = pm_runtime_resume_and_get(&client->dev);
> > > + if (rval < 0)
> > > return rval;
> > > - } else if (!rval) {
> > > +
> > > + if (!rval) {
> > > rval = v4l2_ctrl_handler_setup(&sensor->pixel_array->
> > > ctrl_handler);
> > > if (rval)
> > > @@ -3089,7 +3088,7 @@ static int __maybe_unused ccs_suspend(struct device *dev)
> > > bool streaming = sensor->streaming;
> > > int rval;
> > >
> > > - rval = pm_runtime_get_sync(dev);
> > > + rval = pm_runtime_resume_and_get(dev);
> > > if (rval < 0) {
> > > pm_runtime_put_noidle(dev);
> >
> > You'll need to drop pm_runtime_put_noidle() here.
>
> OK!
>
> ---
>
> On a non-related issue at the same code, after the change, the
> suspend function will be:
>
> static int __maybe_unused ccs_suspend(struct device *dev)
> {
> struct i2c_client *client = to_i2c_client(dev);
> struct v4l2_subdev *subdev = i2c_get_clientdata(client);
> struct ccs_sensor *sensor = to_ccs_sensor(subdev);
> bool streaming = sensor->streaming;
> int rval;
>
> rval = pm_runtime_resume_and_get(dev);
> if (rval < 0)
> return -EAGAIN;
>
> if (sensor->streaming)
> ccs_stop_streaming(sensor);
>
> /* save state for resume */
> sensor->streaming = streaming;
>
> return 0;
> }
>
> Not sure if "return -EAGAIN" is the right thing here. I mean,
> the PM runtime core has two error conditions that are independent
> on whatever the PM callback would be doing[1]:
>
> if (dev->power.runtime_error)
> retval = -EINVAL;
> else if (dev->power.disable_depth > 0)
> retval = -EACCES;
>
> It would be very unlikely that trying to suspend again would solve
> those conditions.
>
> So, I guess that the right thing to do is to change the code
> to do, instead:
>
> static int __maybe_unused ccs_suspend(struct device *dev)
> {
> struct i2c_client *client = to_i2c_client(dev);
> struct v4l2_subdev *subdev = i2c_get_clientdata(client);
> struct ccs_sensor *sensor = to_ccs_sensor(subdev);
> bool streaming = sensor->streaming;
> int rval;
>
> rval = pm_runtime_resume_and_get(dev);
> if (rval < 0)
> return rval;
> ...
> }
>
>
> [1] see rpm_resume() code at drivers/base/power/runtime.c.
Yeah, I agree. This code is one of the older parts the driver.
Please add:
Acked-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
The same goes for the other sensor driver patches in the set you cc'd me,
i.e. patches 12, 15, 26, 28,32, 40, 45, 51, 53 and 55.
--
Kind regards,
Sakari Ailus
