Re: [PATCH v2] iio: adc: stm32-adc: fix check on internal channel availability

[Andy Shevchenko]

On Wed, Sep 16, 2026 at 04:13:23PM +0200, Fabrice Gasnier wrote:
> If an unsupported internal channel like vddgpu is requested, the driver
> prints a warning but falls through and assigns it a valid int_ch below.
> 
> This causes a problem later during setup:
> stm32_adc_int_ch_enable() {
>     ...
>     case STM32_ADC_INT_CH_VDDGPU:
>         stm32_adc_set_bits(adc, adc->cfg->regs->or_vddgpu.reg,
>                            adc->cfg->regs->or_vddgpu.mask);
>     ...
> }
> 
> Because the register offset is uninitialized (0), this performs a
> read-modify-write on offset 0, which corresponds to the ISR register.
> 
> Fix this by returning before a valid int_ch is assigned. Choice is
> made to keep current driver behavior to warn about the channel name.
> 
> Fixes: cf0fb80ae167 ("iio: adc: stm32-adc: add stm32mp13 support")
> Reported-by: Sashiko <sashiko-bot@xxxxxxxxxx>
> Link: https://lore.kernel.org/all/20260911162602.D323F1F000FF@xxxxxxxxxxxxxxx/

Closes: ^^^

> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxxxxxxx>
> ---
> Changes in v2:
> - Review comments from Andy: use bool flag closer to the channel
>   availabilty checks. Add a default case.
> - Link to v1: https://patch.msgid.link/20260915-adc-fix-intchan-v1-v1-1-761a1b35001b@xxxxxxxxxxx

With the above amendment,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxx>

-- 
With Best Regards,
Andy Shevchenko