Re: [PATCH] hwmon: (gpio-fan) return IRQ_HANDLED from the shared alarm IRQ handler

[Guenter Roeck]

On 9/1/26 08:56, Cong Nguyen wrote:
> fan_alarm_irq_handler() is IRQF_SHARED but unconditionally returns
> IRQ_NONE, even though it always schedules work in response. Enough
> "unhandled" reports on a shared line trips the kernel's spurious-
> interrupt detection and disables it, taking every device sharing it
> down too.
>
> Return IRQ_HANDLED, matching what the handler actually does.
>
> Fixes: d6fe1360f42e ("hwmon: add generic GPIO fan driver")
> Reported-by: Sashiko AI review <sashiko-bot@xxxxxxxxxx>
> Link: https://lore.kernel.org/r/20260830152150.27F5F1F000E9@xxxxxxxxxxxxxxx
> Assisted-by: Claude:claude-opus-4
> Signed-off-by: Cong Nguyen <congnt264@xxxxxxxxx>
> ---
>   drivers/hwmon/gpio-fan.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c
> index 084828e1e281..a55a7ea07fc0 100644
> --- a/drivers/hwmon/gpio-fan.c
> +++ b/drivers/hwmon/gpio-fan.c
> @@ -67,7 +67,7 @@ static irqreturn_t fan_alarm_irq_handler(int irq, void *dev_id)
>   
>   	schedule_work(&fan_data->alarm_work);
>   
> -	return IRQ_NONE;
> +	return IRQ_HANDLED;
>   }
>   

That makes me wonder if IRQF_SHARED is appropriate for this driver's
interrupt handler. I think that should be dropped as well.

Thanks,
Guenter

>   static ssize_t fan1_alarm_show(struct device *dev,