From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-3308147-1523479810-2-13831759941735028042 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, MAILING_LIST_MULTI -1, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=fm2; t= 1523479809; b=rdJsX0TDzFVUlXbNoD+NVSfrb2sgFUIQTEauUmcIwzwfZxc7IL qOzJ+UidsxZjhf6TlHKlLYS00J41irIBzU7pH6jaWgu2NODIOvrrx8fC+7C/WTDe SPg7VB9TSnHF9sPnZQ06498s65v2ndqj+N8NvO9BW4PpQB4Kb6Ql4xW0lfbMYt52 BnFo0O+cj9uMLxaZeOF62L0wq1Psy2o46YoR0Qebt2CRECtfZivcjYKxOs5LFhTa vAN7L3uLgAL/n/ubhRDpJDjZOC+RdkGCp2sDOl8vpbrf00LhxsbQzlMMEFOea99f wjLp2LnWwbfebOMfK9J1XEUPVxq3/nKB+shw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type:sender :list-id; s=fm2; t=1523479809; bh=icEpjjEKdOYYZ5KHGQyAxHf4sgFbS+ qSvOUQaTqYMH4=; b=b6qyjuvVvoMF0Y7dnPKGFsfMbJF0Iz5y94OuH3Of/54sHY eEVnwc8RWkj55dfSji5H0gdSwKOGYGu2vhHaVhCHyL8kcLY08W+ItQh08Ru4T5gj 6upLtWhcKE3KzNTqnbBP7gK2RNte5Xy72+C7MEY1yi5jikSlv1NdkNU3K7CquYZE /pap0C8sdimeOWJJyPBBA61I+Pt6kGm4tRIOAZ1mCDvFApWbDfI13RRfyacEvdiV 798qMQvy/BhIQXeeWJAnz/ZjbvF+FtQ8SNcGj58qafyOjCfcfEoqdfZebG79yxGP iRegELjsic6YxnsJ+9jtDUfnBPLZ4d8hzBCYFO2g== ARC-Authentication-Results: i=1; mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfBVkYrXllWhAppq+GqgvE+EKelEj3U52xjAK38hwYbqxySpfj+YxqsxHUBxNPV2gI+CViKXwpHrb/S4romA55rfgCu1KAC0v9rx9xlvijONbOIixMpjm pvXaVSE6w1A+4BIUWDgEFzE2RgCOIlcX7S9qD/fySWgBMnG0yVabDJDg6LQ0CkHCFgwwj6yDPPrQgJkHbLG9OroomvarzPUlxQ490HWJLGjaw/48OlUWHAhq X-CM-Analysis: v=2.3 cv=WaUilXpX c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=IkcTkHD0fZMA:10 a=Kd1tUaAdevIA:10 a=AMTvMMonAAAA:8 a=VwQbUJbxAAAA:8 a=yMhMjlubAAAA:8 a=ag1SF4gXAAAA:8 a=IoLR7627HhPfafYgmrEA:9 a=QEXdDO2ut3YA:10 a=p5oU-coMHzOM5oT1KbOf:22 a=AjGcO6oz07-iQ99wixmX:22 a=Yupwre4RP9_Eg_Bd0iYG:22 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755640AbeDKSp6 (ORCPT ); Wed, 11 Apr 2018 14:45:58 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:58736 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755631AbeDKSpx (ORCPT ); Wed, 11 Apr 2018 14:45:53 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nikita Yushchenko , Jonathan Cameron , Sasha Levin Subject: [PATCH 4.4 055/190] iio: hi8435: avoid garbage event at first enable Date: Wed, 11 Apr 2018 20:35:01 +0200 Message-Id: <20180411183553.570751720@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180411183550.114495991@linuxfoundation.org> References: <20180411183550.114495991@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nikita Yushchenko [ Upstream commit ee19ac340c5fdfd89c6348be4563453c61ab54a9 ] Currently, driver generates events for channels if new reading differs from previous one. This "previous value" is initialized to zero, which results into event if value is constant-one. Fix that by initializing "previous value" by reading at event enable time. This provides reliable sequence for userspace: - enable event, - AFTER THAT read current value, - AFTER THAT each event will correspond to change. Signed-off-by: Nikita Yushchenko Signed-off-by: Jonathan Cameron Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/iio/adc/hi8435.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) --- a/drivers/iio/adc/hi8435.c +++ b/drivers/iio/adc/hi8435.c @@ -121,10 +121,21 @@ static int hi8435_write_event_config(str enum iio_event_direction dir, int state) { struct hi8435_priv *priv = iio_priv(idev); + int ret; + u32 tmp; + + if (state) { + ret = hi8435_readl(priv, HI8435_SO31_0_REG, &tmp); + if (ret < 0) + return ret; + if (tmp & BIT(chan->channel)) + priv->event_prev_val |= BIT(chan->channel); + else + priv->event_prev_val &= ~BIT(chan->channel); - priv->event_scan_mask &= ~BIT(chan->channel); - if (state) priv->event_scan_mask |= BIT(chan->channel); + } else + priv->event_scan_mask &= ~BIT(chan->channel); return 0; }