On Wed, Apr 13, 2022 at 8:09 PM Sakari Ailus
<sakari.ailus@xxxxxxxxxxxxxxx> wrote:
>
> Hi Zheyu,
>
> Thanks for the patch.
>
> On Sat, Apr 09, 2022 at 10:09:39PM +0800, Zheyu Ma wrote:
> > When the driver fails to probe, we will get the following splat:
> >
> > [ 59.305988] ------------[ cut here ]------------
> > [ 59.306417] WARNING: CPU: 2 PID: 395 at drivers/regulator/core.c:2257 _regulator_put+0x3ec/0x4e0
> > [ 59.310345] RIP: 0010:_regulator_put+0x3ec/0x4e0
> > [ 59.318362] Call Trace:
> > [ 59.318582] <TASK>
> > [ 59.318765] regulator_put+0x1f/0x30
> > [ 59.319058] devres_release_group+0x319/0x3d0
> > [ 59.319420] i2c_device_probe+0x766/0x940
> >
> > Fix this by adding a callback that will deal with the disabling when the
> > driver fails to probe.
> >
> > Signed-off-by: Zheyu Ma <zheyuma97@xxxxxxxxx>
> > ---
> > drivers/media/i2c/dw9714.c | 11 +++++++++++
> > 1 file changed, 11 insertions(+)
> >
> > diff --git a/drivers/media/i2c/dw9714.c b/drivers/media/i2c/dw9714.c
> > index cd7008ad8f2f..eccd05fc50c7 100644
> > --- a/drivers/media/i2c/dw9714.c
> > +++ b/drivers/media/i2c/dw9714.c
> > @@ -137,6 +137,13 @@ static int dw9714_init_controls(struct dw9714_device *dev_vcm)
> > return hdl->error;
> > }
> >
> > +static void dw9714_disable_regulator(void *arg)
> > +{
> > + struct dw9714_device *dw9714_dev = arg;
> > +
> > + regulator_disable(dw9714_dev->vcc);
> > +}
> > +
> > static int dw9714_probe(struct i2c_client *client)
> > {
> > struct dw9714_device *dw9714_dev;
> > @@ -157,6 +164,10 @@ static int dw9714_probe(struct i2c_client *client)
> > return rval;
> > }
> >
> > + rval = devm_add_action_or_reset(&client->dev, dw9714_disable_regulator, dw9714_dev);
> > + if (rval)
> > + return rval;
> > +
> > v4l2_i2c_subdev_init(&dw9714_dev->sd, client, &dw9714_ops);
> > dw9714_dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE |
> > V4L2_SUBDEV_FL_HAS_EVENTS;
>
> Could you instead disable the regulator in error handling in the probe
> function?
OK, I will send a v2 patch.
Zheyu Ma
