Re: [PATCH] mfd: da9150: balance IRQ wake on teardown

[Lee Jones <lee@kernel.org>]

On Sat, 12 Sep 2026, Myeonghun Pak wrote:

> DA9150 enables IRQ wake after registering its regmap IRQ chip, but does not
> disable it on a later probe failure or driver removal. This leaves the wake
> depth elevated after the handler is removed, and repeated bind attempts can
> accumulate the imbalance.
> 
> Remember whether enabling IRQ wake succeeded and balance only a successful
> call. Remove MFD children first so their nested IRQ users are gone, then
> disable wake before removing the regmap IRQ chip. Preserve the existing
> non-fatal behavior when IRQ wake cannot be enabled.
> 
> This issue was identified during our ongoing static-analysis research while
> reviewing kernel code.
> 
> Fixes: b8fce55c09d3 ("mfd: Add support for DA9150 combined charger & fuel-gauge device")
> Assisted-by: OpenAI:GPT-5.6
> Co-developed-by: Ijae Kim <ae878000@gmail.com>
> Signed-off-by: Ijae Kim <ae878000@gmail.com>
> Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
> ---
>  drivers/mfd/da9150-core.c       | 9 +++++++--
>  include/linux/mfd/da9150/core.h | 1 +
>  2 files changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mfd/da9150-core.c b/drivers/mfd/da9150-core.c
> index 5c59cc869fb3e..d91d419fea663 100644
> --- a/drivers/mfd/da9150-core.c
> +++ b/drivers/mfd/da9150-core.c
> @@ -450,7 +450,8 @@ static int da9150_probe(struct i2c_client *client)
>  
>  	da9150->irq_base = regmap_irq_chip_get_base(da9150->regmap_irq_data);
>  
> -	enable_irq_wake(da9150->irq);
> +	if (!enable_irq_wake(da9150->irq))
> +		da9150->irq_wake_enabled = true;

da9150->irq_wake_enabled = !enable_irq_wake(da9150->irq);

>  	ret = mfd_add_devices(da9150->dev, -1, da9150_devs,
>  			      ARRAY_SIZE(da9150_devs), NULL,
> @@ -463,6 +464,8 @@ static int da9150_probe(struct i2c_client *client)
>  	return 0;
>  
>  mfd_fail:
> +	if (da9150->irq_wake_enabled)
> +		disable_irq_wake(da9150->irq);

Or drop all of the checks and just call disable_irq_wake() on the error path.

>  	regmap_del_irq_chip(da9150->irq, da9150->regmap_irq_data);
>  regmap_irq_fail:
>  	i2c_unregister_device(da9150->core_qif);
> @@ -474,8 +477,10 @@ static void da9150_remove(struct i2c_client *client)
>  {
>  	struct da9150 *da9150 = i2c_get_clientdata(client);
>  
> -	regmap_del_irq_chip(da9150->irq, da9150->regmap_irq_data);
>  	mfd_remove_devices(da9150->dev);
> +	if (da9150->irq_wake_enabled)
> +		disable_irq_wake(da9150->irq);
> +	regmap_del_irq_chip(da9150->irq, da9150->regmap_irq_data);
>  	i2c_unregister_device(da9150->core_qif);
>  }
>  
> diff --git a/include/linux/mfd/da9150/core.h b/include/linux/mfd/da9150/core.h
> index d116d5f3ef561..369698036d1aa 100644
> --- a/include/linux/mfd/da9150/core.h
> +++ b/include/linux/mfd/da9150/core.h
> @@ -65,6 +65,7 @@ struct da9150 {
>  	struct regmap_irq_chip_data *regmap_irq_data;
>  	int irq;
>  	int irq_base;
> +	bool irq_wake_enabled;
>  };
>  
>  /* Device I/O - Query Interface for FG and standard register access */
> -- 
> 2.47.1
> 

-- 
Lee Jones