linux-kernel - Re: [PATCH] input: cypress-sf: Register a callback to disable the regulators

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Date:   Fri, 8 Apr 2022 19:34:09 -0700
From:   Dmitry Torokhov <dmitry.torokhov@...il.com>
To:     Zheyu Ma <zheyuma97@...il.com>
Cc:     y.oudjana@...tonmail.com, linux-input@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] input: cypress-sf: Register a callback to disable the
 regulators

Hi Zheyu,

On Sat, Apr 09, 2022 at 10:26:29AM +0800, Zheyu Ma wrote:
> When the driver fails to probe, we will get the following splat:
> 
> [   19.311970] ------------[ cut here ]------------
> [   19.312566] WARNING: CPU: 3 PID: 375 at drivers/regulator/core.c:2257 _regulator_put+0x3ec/0x4e0
> [   19.317591] RIP: 0010:_regulator_put+0x3ec/0x4e0
> [   19.328831] Call Trace:
> [   19.329112]  <TASK>
> [   19.329369]  regulator_bulk_free+0x82/0xe0
> [   19.329860]  devres_release_group+0x319/0x3d0
> [   19.330357]  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@...il.com>
> ---
>  drivers/input/keyboard/cypress-sf.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/input/keyboard/cypress-sf.c b/drivers/input/keyboard/cypress-sf.c
> index c28996028e80..798611b76de6 100644
> --- a/drivers/input/keyboard/cypress-sf.c
> +++ b/drivers/input/keyboard/cypress-sf.c
> @@ -61,6 +61,13 @@ static irqreturn_t cypress_sf_irq_handler(int irq, void *devid)
>  	return IRQ_HANDLED;
>  }
>  
> +static void cypress_sf_disable_regulator(void *arg)
> +{
> +	struct cypress_sf_data *data = arg;
> +
> +	regulator_bulk_disable(ARRAY_SIZE(data->regulators), data->regulators);
> +}
> +
>  static int cypress_sf_probe(struct i2c_client *client)
>  {
>  	struct cypress_sf_data *touchkey;
> @@ -84,6 +91,10 @@ static int cypress_sf_probe(struct i2c_client *client)
>  		return error;
>  	}
>  
> +	error = devm_add_action_or_reset(&client->dev, cypress_sf_disable_regulator, touchkey);
> +	if (error)
> +		return error;

This needs to be moved to the spot after we enabled regulators. I
adjusted and applied.

> +
>  	touchkey->num_keys = device_property_read_u32_array(&client->dev,
>  							    "linux,keycodes",
>  							    NULL, 0);
> -- 
> 2.25.1
> 

Thanks.

-- 
Dmitry