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=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED 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 5B9D0C43143 for ; Sat, 29 Sep 2018 11:31:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2296A2084D for ; Sat, 29 Sep 2018 11:31:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="x2MLRemh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2296A2084D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.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 S1728152AbeI2R7S (ORCPT ); Sat, 29 Sep 2018 13:59:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:41940 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727872AbeI2R7S (ORCPT ); Sat, 29 Sep 2018 13:59:18 -0400 Received: from archlinux (cpc91196-cmbg18-2-0-cust659.5-4.cable.virginm.net [81.96.234.148]) (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 49F2E2073F; Sat, 29 Sep 2018 11:31:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1538220671; bh=a8qSyKtkOc2IbusDHpELkozS+nhC1lFzPXgdcFZF47M=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=x2MLRemhZ3jmx+CDgoj0iT4FPrUJnTq39vRAiQeOjNzS8v/7zY9X2aZUu172/xjWo ki9SoNfR2XIShK3I2zag99bPQHturA9O2ILEEdrv0y92fJM02ihfGdES31Ml8mnZ72 PXTxw3FfDbViGwqNBXPNg9h/prXbfMfdeVKgX9SE= Date: Sat, 29 Sep 2018 12:31:07 +0100 From: Jonathan Cameron To: Ludovic Desroches Cc: Eugen Hristev , , , , , Maxime Ripard Subject: Re: [PATCH v2 1/2] iio: adc: at91: fix acking DRDY irq on simple conversions Message-ID: <20180929123107.0d0053e3@archlinux> In-Reply-To: <20180925131739.2nuoelhqmkszamqo@M43218.corp.atmel.com> References: <1537775504-7981-1-git-send-email-eugen.hristev@microchip.com> <20180925131739.2nuoelhqmkszamqo@M43218.corp.atmel.com> X-Mailer: Claws Mail 3.17.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 25 Sep 2018 15:17:39 +0200 Ludovic Desroches wrote: > On Mon, Sep 24, 2018 at 10:51:43AM +0300, Eugen Hristev wrote: > > 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 Applied to the togreg branch of iio.git and marked for stable. It's been broken long enough that I think it can wait for the merge window coming in a few weeks time. Thanks, Jonathan > > > --- > > 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 > >