Re: [PATCH] iio: adc: at91: unbreak channel adc channel 3

[Alexandre Belloni]

On 08/08/2016 at 14:42:16 +0200, Anders Darander wrote :
> The driver always assumes that an input device has been created when
> reading channel 3. This causes a kernel panic when dereferencing
> st->ts_input.
> 
> The change was introduced in
> commit 84882b060301 ("iio: adc: at91_adc: Add support for touchscreens
> without TSMR"). Earlier versions only entered that part of the if-else
> statement if only the following flags are set:
> 
> AT91_ADC_IER_XRDY | AT91_ADC_IER_YRDY | AT91_ADC_IER_PRDY
> 
> Signed-off-by: Anders Darander <anders@xxxxxxxxxxxxxx>
Acked-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>

> ---
>  drivers/iio/adc/at91_adc.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
> index 52430ba..0438c68 100644
> --- a/drivers/iio/adc/at91_adc.c
> +++ b/drivers/iio/adc/at91_adc.c
> @@ -381,8 +381,8 @@ static irqreturn_t at91_adc_rl_interrupt(int irq, void *private)
>  		st->ts_bufferedmeasure = false;
>  		input_report_key(st->ts_input, BTN_TOUCH, 0);
>  		input_sync(st->ts_input);
> -	} else if (status & AT91_ADC_EOC(3)) {
> -		/* Conversion finished */
> +	} else if (status & AT91_ADC_EOC(3) && st->ts_input) {
> +		/* Conversion finished and we've a touchscreen */
>  		if (st->ts_bufferedmeasure) {
>  			/*
>  			 * Last measurement is always discarded, since it can
> -- 
> 2.8.1
> 

-- 
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com