iio: adc: stm32-adc: fix check on internal channel availability

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@kernel.org>
Closes: https://lore.kernel.org/all/20260911162602.D323F1F000FF@smtp.kernel.org/
Cc: stable@vger.kernel.org
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Signed-off-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

0 files changed, 0 insertions, 0 deletions