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authorEugen Hristev <eugen.hristev@microchip.com>2018-09-24 10:51:43 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-11-22 09:32:44 +0300
commitebfe1077bdcc19be09f1aae4d55182692892cd4b (patch)
tree71d625be877bdfe327ea543e6b94935171f86f96 /drivers/iio/adc
parentb4e60099f144458e01460515de4dac9c3d662e51 (diff)
downloadlinux-ebfe1077bdcc19be09f1aae4d55182692892cd4b.tar.xz
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 <maxime.ripard@bootlin.com> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com> Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com> Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/iio/adc')
-rw-r--r--drivers/iio/adc/at91_adc.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
index 0047db49ee5e..b5885645ecfe 100644
--- a/drivers/iio/adc/at91_adc.c
+++ b/drivers/iio/adc/at91_adc.c
@@ -276,6 +276,8 @@ 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);
}