From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35F23C433F4 for ; Mon, 24 Sep 2018 07:57:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EE7BB2146D for ; Mon, 24 Sep 2018 07:57:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EE7BB2146D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=microchip.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727519AbeIXN6S (ORCPT ); Mon, 24 Sep 2018 09:58:18 -0400 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 X-IronPort-AV: E=Sophos;i="5.54,297,1534834800"; d="scan'208";a="18307557" Received: from smtpout.microchip.com (HELO email.microchip.com) ([198.175.253.82]) by esa5.microchip.iphmx.com with ESMTP/TLS/DHE-RSA-AES256-SHA; 24 Sep 2018 00:57:28 -0700 Received: from eh-station.microchip.com (10.10.76.4) by chn-sv-exch02.mchp-main.com (10.10.76.38) with Microsoft SMTP Server id 14.3.352.0; Mon, 24 Sep 2018 00:57:26 -0700 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> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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