Messages in this thread Patch in this message | | | Date | Tue, 25 Sep 2018 15:17:39 +0200 | From | Ludovic Desroches <> | Subject | Re: [PATCH v2 1/2] iio: adc: at91: fix acking DRDY irq on simple conversions |
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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 <maxime.ripard@bootlin.com> > Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com> Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
> --- > 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@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 >
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