[PATCH v2 1/2] iio: adc: at91: fix acking DRDY irq on simple conversions
From: ludovic.desroches@microchip.com (Ludovic Desroches)
Date: 2018-09-25 13:17:43
Also in:
linux-iio, lkml
On Mon, Sep 24, 2018 at 10:51:43AM +0300, Eugen Hristev wrote:
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 <redacted>
Signed-off-by: Eugen Hristev <redacted>Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
quoted hunk ↗ jump to hunk
--- Hello Jonathan, I moved this LCDR read/acknowledge into the IRQ handler after the conversion value is being read. Sorry about the noise to stable at vger, removed from message. Thanks, Eugen 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 44b5168..e3be88e 100644 --- a/drivers/iio/adc/at91_adc.c +++ b/drivers/iio/adc/at91_adc.c@@ -279,6 +279,8 @@ static void handle_adc_eoc_trigger(int irq, struct iio_dev *idev) iio_trigger_poll(idev->trig); } 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); }-- 2.7.4