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=-6.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 AD747C43441 for ; Sun, 11 Nov 2018 23:21:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 75A1020817 for ; Sun, 11 Nov 2018 23:21:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="OkBp4qen" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 75A1020817 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org 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 S2389416AbeKLIVL (ORCPT ); Mon, 12 Nov 2018 03:21:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:47478 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389356AbeKLIVI (ORCPT ); Mon, 12 Nov 2018 03:21:08 -0500 Received: from localhost (unknown [206.108.79.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E952A223CB; Sun, 11 Nov 2018 22:31:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541975472; bh=PbsiiwDUs87aZbTEddjAMg3b7oxG2C9HN0vOkUJlio0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OkBp4qenucq3a4x6MdXvAhp3CEf+tyZ8nibt2hz1ARShcf9i1hljd4cMAjlebgZKE pVJx73fuFRIS7bRgu+TVK2C/FHdNy13mHfQ/+eSEpYIiZ9PT7XttmAX0l2MbU7NEQy +lEnMOpAdCCjz1qkbO4HC7hLFcM6AYh2eyJzhaKM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Maxime Ripard , Eugen Hristev , Ludovic Desroches , Stable@vger.kernel.org, Jonathan Cameron Subject: [PATCH 4.18 253/350] iio: adc: at91: fix acking DRDY irq on simple conversions Date: Sun, 11 Nov 2018 14:21:57 -0800 Message-Id: <20181111221718.619089582@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181111221707.043394111@linuxfoundation.org> References: <20181111221707.043394111@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eugen Hristev 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 Signed-off-by: Eugen Hristev Acked-by: Ludovic Desroches Cc: Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/adc/at91_adc.c | 2 ++ 1 file changed, 2 insertions(+) --- 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 i 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); }