Hi Laurent,
Am Montag, 16. Januar 2023, 12:49:22 CET schrieb Laurent Pinchart:
> Hi Alexander,
>
> On Mon, Jan 16, 2023 at 12:14:46PM +0100, Alexander Stein wrote:
> > Am Samstag, 14. Januar 2023, 18:17:59 CET schrieb Laurent Pinchart:
> > > Initializing the subdev before runtime PM means that no subdev
> > > initialization can interact with the runtime PM framework. This can be
> > > problematic when modifying controls, as the .s_ctrl() handler commonly
> > > calls pm_runtime_get_if_in_use(). These code paths are not trivial,
> > > making the driver fragile and possibly causing subtle bugs.
> > >
> > > To make the subdev initialization more robust, initialize runtime PM
> > > first.
> > >
> > > Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> >
> > Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
>
> Thank you for giving me my own ack, but yours would be more useful :-)
oh... Sorry. I messed up my copy and paste :(
Acked-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>
> > > ---
> > >
> > > drivers/media/i2c/imx290.c | 57 ++++++++++++++++++++++----------------
> > > 1 file changed, 33 insertions(+), 24 deletions(-)
> > >
> > > diff --git a/drivers/media/i2c/imx290.c b/drivers/media/i2c/imx290.c
> > > index 6a3e93c10fb1..c3ffb23104bf 100644
> > > --- a/drivers/media/i2c/imx290.c
> > > +++ b/drivers/media/i2c/imx290.c
> > > @@ -581,9 +581,7 @@ static int imx290_set_ctrl(struct v4l2_ctrl *ctrl)
> > >
> > > /*
> > >
> > > * Return immediately for controls that don't need to be applied to
> > > the
> > >
> > > - * device. This includes all controls modified in
> > > imx290_ctrl_update(),
> > > - * which is called at probe time before runtime PM is initialized,
so
> > > - * we can't proceed to the pm_runtime_get_if_in_use() call below.
> > > + * device.
> > >
> > > */
> > >
> > > switch (ctrl->id) {
> > >
> > > case V4L2_CID_LINK_FREQ:
> > > @@ -1054,22 +1052,20 @@ static void imx290_subdev_cleanup(struct imx290
> > > *imx290)> >
> > > * Power management
> > > */
> > >
> > > -static int imx290_power_on(struct device *dev)
> > > +static int imx290_power_on(struct imx290 *imx290)
> > >
> > > {
> > >
> > > - struct v4l2_subdev *sd = dev_get_drvdata(dev);
> > > - struct imx290 *imx290 = to_imx290(sd);
> > >
> > > int ret;
> > >
> > > ret = clk_prepare_enable(imx290->xclk);
> > > if (ret) {
> > >
> > > - dev_err(dev, "Failed to enable clock\n");
> > > + dev_err(imx290->dev, "Failed to enable clock\n");
> > >
> > > return ret;
> > >
> > > }
> > >
> > > ret = regulator_bulk_enable(ARRAY_SIZE(imx290->supplies),
> > >
> > > imx290->supplies);
> > >
> > > if (ret) {
> > >
> > > - dev_err(dev, "Failed to enable regulators\n");
> > > + dev_err(imx290->dev, "Failed to enable regulators\n");
> > >
> > > clk_disable_unprepare(imx290->xclk);
> > > return ret;
> > >
> > > }
> > >
> > > @@ -1084,20 +1080,33 @@ static int imx290_power_on(struct device *dev)
> > >
> > > return 0;
> > >
> > > }
> > >
> > > -static int imx290_power_off(struct device *dev)
> > > +static void imx290_power_off(struct imx290 *imx290)
> > >
> > > {
> > >
> > > - struct v4l2_subdev *sd = dev_get_drvdata(dev);
> > > - struct imx290 *imx290 = to_imx290(sd);
> > > -
> > >
> > > clk_disable_unprepare(imx290->xclk);
> > > gpiod_set_value_cansleep(imx290->rst_gpio, 1);
> > > regulator_bulk_disable(ARRAY_SIZE(imx290->supplies),
> > > imx290->supplies);
> > >
> > > +}
> > > +
> > > +static int imx290_runtime_resume(struct device *dev)
> > > +{
> > > + struct v4l2_subdev *sd = dev_get_drvdata(dev);
> > > + struct imx290 *imx290 = to_imx290(sd);
> > > +
> > > + return imx290_power_on(imx290);
> > > +}
> > > +
> > > +static int imx290_runtime_suspend(struct device *dev)
> > > +{
> > > + struct v4l2_subdev *sd = dev_get_drvdata(dev);
> > > + struct imx290 *imx290 = to_imx290(sd);
> > > +
> > > + imx290_power_off(imx290);
> > >
> > > return 0;
> > >
> > > }
> > >
> > > static const struct dev_pm_ops imx290_pm_ops = {
> > >
> > > - SET_RUNTIME_PM_OPS(imx290_power_off, imx290_power_on, NULL)
> > > + SET_RUNTIME_PM_OPS(imx290_runtime_suspend, imx290_runtime_resume,
> > > NULL)
> > >
> > > };
> > >
> > > /*
> > > ----------------------------------------------------------------------
> > > ------> >
> > > @@ -1276,20 +1285,15 @@ static int imx290_probe(struct i2c_client
> > > *client)
> > > if (ret)
> > >
> > > return ret;
> > >
> > > - /* Initialize the V4L2 subdev. */
> > > - ret = imx290_subdev_init(imx290);
> > > - if (ret)
> > > - return ret;
> > > -
> > >
> > > /*
> > >
> > > * Enable power management. The driver supports runtime PM, but
needs
> > > to
> > > * work when runtime PM is disabled in the kernel. To that end,
power
> > > * the sensor on manually here.
> > > */
> > >
> > > - ret = imx290_power_on(dev);
> > > + ret = imx290_power_on(imx290);
> > >
> > > if (ret < 0) {
> > >
> > > dev_err(dev, "Could not power on the device\n");
> > >
> > > - goto err_subdev;
> > > + return ret;
> > >
> > > }
> > >
> > > /*
> > >
> > > @@ -1303,6 +1307,11 @@ static int imx290_probe(struct i2c_client
> > > *client)
> > >
> > > pm_runtime_set_autosuspend_delay(dev, 1000);
> > > pm_runtime_use_autosuspend(dev);
> > >
> > > + /* Initialize the V4L2 subdev. */
> > > + ret = imx290_subdev_init(imx290);
> > > + if (ret)
> > > + goto err_pm;
> > > +
> > >
> > > /*
> > >
> > > * Finally, register the V4L2 subdev. This must be done after
> > > * initializing everything as the subdev can be used immediately
after
> > >
> > > @@ -1323,12 +1332,12 @@ static int imx290_probe(struct i2c_client
> > > *client)
> > >
> > > return 0;
> > >
> > > +err_subdev:
> > > + imx290_subdev_cleanup(imx290);
> > >
> > > err_pm:
> > > pm_runtime_disable(dev);
> > > pm_runtime_put_noidle(dev);
> > >
> > > - imx290_power_off(dev);
> > > -err_subdev:
> > > - imx290_subdev_cleanup(imx290);
> > > + imx290_power_off(imx290);
> > >
> > > return ret;
> > >
> > > }
> > >
> > > @@ -1346,7 +1355,7 @@ static void imx290_remove(struct i2c_client
> > > *client)
> > >
> > > */
> > >
> > > pm_runtime_disable(imx290->dev);
> > > if (!pm_runtime_status_suspended(imx290->dev))
> > >
> > > - imx290_power_off(imx290->dev);
> > > + imx290_power_off(imx290);
> > >
> > > pm_runtime_set_suspended(imx290->dev);
> > >
> > > }
