From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa5.microchip.iphmx.com ([216.71.150.166]:38679 "EHLO esa5.microchip.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725935AbeIXN6R (ORCPT ); Mon, 24 Sep 2018 09:58:17 -0400 From: Eugen Hristev To: , , , , CC: , Eugen Hristev , Maxime Ripard Subject: [PATCH v2 1/2] iio: adc: at91: fix acking DRDY irq on simple conversions Date: Mon, 24 Sep 2018 10:51:43 +0300 Message-ID: <1537775504-7981-1-git-send-email-eugen.hristev@microchip.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org 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 --- 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