2022-04-11 02:16:13

by Zheyu Ma

Subject: [PATCH] media: i2c: dw9714: Register a callback to disable the regulator

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 <[email protected]>
---
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;
--
2.25.1

2022-04-14 05:43:07

by Sakari Ailus

Subject: Re: [PATCH] media: i2c: dw9714: Register a callback to disable the regulator

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 <[email protected]>
> ---
> 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?

--
Sakari Ailus

2022-04-14 15:40:49

by Zheyu Ma

Subject: Re: [PATCH] media: i2c: dw9714: Register a callback to disable the regulator

On Wed, Apr 13, 2022 at 8:09 PM Sakari Ailus
<[email protected]> 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 <[email protected]>
> > ---
> > 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