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=-7.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS 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 41B9DC43441 for ; Sun, 11 Nov 2018 16:03:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F3B93214DE for ; Sun, 11 Nov 2018 16:03:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="jpjU/cf1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F3B93214DE 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 S1728809AbeKLBwB (ORCPT ); Sun, 11 Nov 2018 20:52:01 -0500 Received: from mail.kernel.org ([198.145.29.99]:32800 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728712AbeKLBwB (ORCPT ); Sun, 11 Nov 2018 20:52:01 -0500 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 D180D2148E; Sun, 11 Nov 2018 16:03:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541952185; bh=VNeyg8NSZeRmrbVaYIFI39QVs1frkLEKCLsu2UGobsA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=jpjU/cf1BPzfK2vTywWtne5dItEm2oaM/4UX+uaA6MwIyux2Mc0b6oBVjGxIkfhRf lQAJqYc9dcHezfNKzWCOdLdSAc1ynicmXCywY/piNU4jHqGGGNeA5+BAiA4eEj0OEQ 3vV9VHzfC5lqDTv2yk9lSFu/G7f57feN9YdXX1/k= Date: Sun, 11 Nov 2018 16:03:00 +0000 From: Jonathan Cameron To: Baolin Wang Cc: Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , freeman.liu@unisoc.com, Mark Brown , linux-iio@vger.kernel.org, LKML Subject: Re: [PATCH] iio: adc: sc27xx: Add ADC data conversion timeout Message-ID: <20181111160300.3193196c@archlinux> In-Reply-To: References: <208f9043fbd9b14b7a0c2743f68fa424388f5dcd.1541733478.git.baolin.wang@linaro.org> <20181111124044.52f61897@archlinux> 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 Sun, 11 Nov 2018 23:00:18 +0800 Baolin Wang wrote: > Hi Jonathan, > > On 11 November 2018 at 20:40, Jonathan Cameron wrote: > > On Fri, 9 Nov 2018 11:25:31 +0800 > > Baolin Wang wrote: > > > >> From: Freeman Liu > >> > >> Sometimes the ADC controller met some problems, and it will not complete > >> the data conversion, that will can not wake up the read process any more > >> to block users. So we should add one maximum conversion time to avoid > >> this issue. > >> > >> Signed-off-by: Freeman Liu > >> Signed-off-by: Baolin Wang > > Hi. > > > > Patch looks good, but sounds like this is a fix so could I have a fixes > > tag and a patch title that makes that clear? > > > > I think we will want this one back ported to stable by the sound of it. > > > > If it is just a theoretical issue then perhaps we don't need to bother. > > Thanks for your review. This patch is not one bug fix, just make the > code more robust in case of some bad cases. So I think we do not need > the stable tag. Thanks. Applied to the togreg branch of iio.git and pushed out as testing for the autobuilders to play with it. Jonathan > > > > > Thanks, > > > > Jonathan > > > >> --- > >> drivers/iio/adc/sc27xx_adc.c | 12 +++++++++++- > >> 1 file changed, 11 insertions(+), 1 deletion(-) > >> > >> diff --git a/drivers/iio/adc/sc27xx_adc.c b/drivers/iio/adc/sc27xx_adc.c > >> index 7940b23..f7f7a189 100644 > >> --- a/drivers/iio/adc/sc27xx_adc.c > >> +++ b/drivers/iio/adc/sc27xx_adc.c > >> @@ -52,6 +52,9 @@ > >> /* Timeout (ms) for the trylock of hardware spinlocks */ > >> #define SC27XX_ADC_HWLOCK_TIMEOUT 5000 > >> > >> +/* Timeout (ms) for ADC data conversion according to ADC datasheet */ > >> +#define SC27XX_ADC_RDY_TIMEOUT 100 > >> + > >> /* Maximum ADC channel number */ > >> #define SC27XX_ADC_CHANNEL_MAX 32 > >> > >> @@ -223,7 +226,14 @@ static int sc27xx_adc_read(struct sc27xx_adc_data *data, int channel, > >> if (ret) > >> goto disable_adc; > >> > >> - wait_for_completion(&data->completion); > >> + ret = wait_for_completion_timeout(&data->completion, > >> + msecs_to_jiffies(SC27XX_ADC_RDY_TIMEOUT)); > >> + if (!ret) { > >> + dev_err(data->dev, "read ADC data timeout\n"); > >> + ret = -ETIMEDOUT; > >> + } else { > >> + ret = 0; > >> + } > >> > >> disable_adc: > >> regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL, > > > > >