[PATCH v2] iio: adc: stm32-adc: Fix race in installing chained IRQ handler

[Jonathan Cameron]

On Mon, 26 May 2025 17:48:31 +0200
Fabrice Gasnier <fabrice.gasnier at foss.st.com> wrote:

> On 5/25/25 13:07, Jonathan Cameron wrote:
> > On Thu, 15 May 2025 11:26:56 +0100
> > Nuno Sá <noname.nuno at gmail.com> wrote:
> >   
> >> On Thu, 2025-05-15 at 16:31 +0800, Chen Ni wrote:  
> >>> Fix a race where a pending interrupt could be received and the handler
> >>> called before the handler's data has been setup, by converting to
> >>> irq_set_chained_handler_and_data().
> >>>
> >>> Fixes: d58c67d1d851 ("iio: adc: stm32-adc: add support for STM32MP1")
> >>> Signed-off-by: Chen Ni <nichen at iscas.ac.cn>
> >>> ---    
> >>
> >> Reviewed-by: Nuno Sá <nuno.sa at analog.com>  
> > Looks good to me and I've queued it up for after rc1.  If any
> > ST folk have time to take a look that would be great.  
> 
> Hi Jonathan,
> 
> One minor comment at my end, not sure if that changes a lot...
> This could be a fix for the older commit:
> 1add69880240 ("iio: adc: Add support for STM32 ADC core")

Agreed. I've tweaked the message.  It won't apply cleanly all that way
but at least we flagged it for anyone who cares to backport past the code
movement in the Fixes tag Chen used.

> 
> Apart from that, you can add my:
> Tested-by: Fabrice Gasnier <fabrice.gasnier at foss.st.com>
> Reviewed-by: Fabrice Gasnier <fabrice.gasnier at foss.st.com>
Added.
> 
> BR,
> Fabrice
> 
> > 
> > Jonathan
> >   
> >>  
> >>> Changelog:
> >>>
> >>> v1 -> v2:
> >>>
> >>> 1. Add Fixes tag.
> >>> ---
> >>>  drivers/iio/adc/stm32-adc-core.c | 7 +++----
> >>>  1 file changed, 3 insertions(+), 4 deletions(-)
> >>>
> >>> diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-
> >>> core.c
> >>> index bd3458965bff..21c04a98b3b6 100644
> >>> --- a/drivers/iio/adc/stm32-adc-core.c
> >>> +++ b/drivers/iio/adc/stm32-adc-core.c
> >>> @@ -430,10 +430,9 @@ static int stm32_adc_irq_probe(struct platform_device
> >>> *pdev,
> >>>  		return -ENOMEM;
> >>>  	}
> >>>  
> >>> -	for (i = 0; i < priv->cfg->num_irqs; i++) {
> >>> -		irq_set_chained_handler(priv->irq[i], stm32_adc_irq_handler);
> >>> -		irq_set_handler_data(priv->irq[i], priv);
> >>> -	}
> >>> +	for (i = 0; i < priv->cfg->num_irqs; i++)
> >>> +		irq_set_chained_handler_and_data(priv->irq[i],
> >>> +						 stm32_adc_irq_handler,
> >>> priv);
> >>>  
> >>>  	return 0;
> >>>  }    
> >   
>