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

[Jonathan Cameron <jic23@kernel.org>]

On 08/08/16 14:52, Alexandre Belloni wrote:
> 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@chargestorm.se>
> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Applied and marked for stable.

Thanks in particular for the thorough description!

Jonathan
> 
>> ---
>>  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
>>
>