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=-7.5 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 BE0F0C43441 for ; Mon, 19 Nov 2018 17:04:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 80B78214E0 for ; Mon, 19 Nov 2018 17:04:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="muvov+9y" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 80B78214E0 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 S2406523AbeKTD2j (ORCPT ); Mon, 19 Nov 2018 22:28:39 -0500 Received: from mail.kernel.org ([198.145.29.99]:43050 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406494AbeKTD2i (ORCPT ); Mon, 19 Nov 2018 22:28:38 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (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 2A6E92146D; Mon, 19 Nov 2018 17:04:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1542647061; bh=KAYOIM3BxHanHeiUM824R3ME1CIPfgzqSb7w4ygfFvg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=muvov+9ySiB26Xrj1YKqPKw9xolqYdzK8Pr74AeV5kP7EVbBvl+8V7BeblyQsH48k /mlJwk1FhGpDUGwZ3U7J0sKJGdbAE7YYc/COzokzjg9wSGsLqEnlaZYPX0oxEDfxTg FNEdIhKAefQZw6gOMfd80DW1Ed32jeCONPWQDB5M= 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 3.18 36/90] iio: adc: at91: fix acking DRDY irq on simple conversions Date: Mon, 19 Nov 2018 17:29:18 +0100 Message-Id: <20181119162626.667625701@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181119162620.585061184@linuxfoundation.org> References: <20181119162620.585061184@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 3.18-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 @@ -276,6 +276,8 @@ 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); }