From 07075af4d48d170cf6800d92f075cb75ba70f2e3 Mon Sep 17 00:00:00 2001 From: Eugen Hristev Date: Mon, 24 Sep 2018 10:51:43 +0300 Subject: [PATCH] iio: adc: at91: fix acking DRDY irq on simple conversions commit bc1b45326223e7e890053cf6266357adfa61942d upstream. When doing simple conversions, the driver did not acknowledge the DRDY irq. If this irq status is not acked, it will be left pending, and as soon as a trigger is enabled, the irq handler will be called, it doesn't know why this status has occurred because no channel is pending, and then it will go int a irq loop and board will hang. To avoid this situation, read the LCDR after a raw conversion is done. Fixes: 0e589d5fb ("ARM: AT91: IIO: Add AT91 ADC driver.") Cc: Maxime Ripard Signed-off-by: Eugen Hristev Acked-by: Ludovic Desroches Signed-off-by: Jonathan Cameron Signed-off-by: Ben Hutchings --- drivers/iio/adc/at91_adc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c index e98515fc469f..90996703441d 100644 --- a/drivers/iio/adc/at91_adc.c +++ b/drivers/iio/adc/at91_adc.c @@ -276,6 +276,8 @@ void handle_adc_eoc_trigger(int irq, struct iio_dev *idev) iio_trigger_poll(idev->trig, iio_get_time_ns()); } else { st->last_value = at91_adc_readl(st, AT91_ADC_CHAN(st, st->chnb)); + /* Needed to ACK the DRDY interruption */ + at91_adc_readl(st, AT91_ADC_LCDR); st->done = true; wake_up_interruptible(&st->wq_data_avail); }