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=-5.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 D4D22C64E7A for ; Tue, 1 Dec 2020 17:38:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 607D420671 for ; Tue, 1 Dec 2020 17:38:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="nnRuEBU8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391945AbgLARiW (ORCPT ); Tue, 1 Dec 2020 12:38:22 -0500 Received: from a2.mail.mailgun.net ([198.61.254.61]:34363 "EHLO a2.mail.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390726AbgLARiW (ORCPT ); Tue, 1 Dec 2020 12:38:22 -0500 X-Greylist: delayed 360 seconds by postgrey-1.27 at vger.kernel.org; Tue, 01 Dec 2020 12:38:22 EST DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1606844276; h=Content-Transfer-Encoding: Content-Type: In-Reply-To: MIME-Version: Date: Message-ID: From: References: Cc: To: Subject: Sender; bh=K1x8lx2ayye4/N0xNELnpa6CNM0J4yfcDBWhh1G+S30=; b=nnRuEBU8X2hNdPJDkpZpfrY6i8Xd5bV1+i9ymFB+EgIcX9/KHbogOhoAhZNTG5f851aDzqsT KD9Gyvq9fF+E1bdqf5mD32rluEIDSG2fYfHNLhALu0YvLsk6IuZSdFHdc98Lax+nSD7jextH WVHB2fWGZ7eDdtXxgg/REqKtaSc= X-Mailgun-Sending-Ip: 198.61.254.61 X-Mailgun-Sid: WyI1YmJiNiIsICJkZXZpY2V0cmVlQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n10.prod.us-east-1.postgun.com with SMTP id 5fc67df3edac2724d86d40e4 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 01 Dec 2020 17:31:31 GMT Sender: srivasam=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 0547DC43462; Tue, 1 Dec 2020 17:31:30 +0000 (UTC) Received: from [172.20.10.2] (unknown [27.59.188.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: srivasam) by smtp.codeaurora.org (Postfix) with ESMTPSA id 47E31C43460; Tue, 1 Dec 2020 17:31:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 47E31C43460 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=srivasam@codeaurora.org Subject: Re: [PATCH v4 1/2] Partially revert ASoC: qcom: Fix enabling BCLK and LRCLK in LPAIF invalid state To: Mark Brown Cc: agross@kernel.org, bjorn.andersson@linaro.org, lgirdwood@gmail.com, robh+dt@kernel.org, plai@codeaurora.org, bgoswami@codeaurora.org, perex@perex.cz, tiwai@suse.com, srinivas.kandagatla@linaro.org, rohitkr@codeaurora.org, linux-arm-msm@vger.kernel.org, alsa-devel@alsa-project.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, V Sujith Kumar Reddy References: <1606539559-4277-1-git-send-email-srivasam@codeaurora.org> <1606539559-4277-2-git-send-email-srivasam@codeaurora.org> <20201130124617.GC4756@sirena.org.uk> From: Srinivasa Rao Mandadapu Organization: Qualcomm India Private Limited. Message-ID: <966993b7-4720-bdd2-cf4d-cf5a7c11a0c1@codeaurora.org> Date: Tue, 1 Dec 2020 23:01:21 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: <20201130124617.GC4756@sirena.org.uk> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Thanks Mark for your time!!! On 11/30/2020 6:16 PM, Mark Brown wrote: > On Sat, Nov 28, 2020 at 10:29:18AM +0530, Srinivasa Rao Mandadapu wrote: >> This reverts part of commit b1824968221c >> ("ASoC: qcom: Fix enabling BCLK and LRCLK in LPAIF invalid state") >> >> To identify LPAIF invalid state after device suspend and resume, >> made I2S and DMA control registers not volatile, which is not necessary. >> Instead invalid reg state can be handled with regcache APIs. >> The BCLK ref count is necessary to enable clock only it's in disable state. > Part of this commit message says that the problem was making the registers > non-volatile but both the change and the rest of the commit message say > that the issue was that the registers were made volatile. I'm also > still unclear as to what the issue is either way - how does reading the > state of the registers from the hardware instead of the cache affect > things? Initial problem was, during playback if device suspended, I2S and DMA control registers are getting reset and unable to recover playback after resume. As these registers were non volatile registers, driver is not getting actual register value and unable to report error state to application. Due to this application keeps on polling for HW current pointer state and not exited from PCM running state. To handle this scenario I made registers volatile and if they are in reset state, reported error to application(commit b1824968221c). Later from review comments by Srinivas kandagatla, I got to know about regcache sync APIs, which can be used  to sync cache after resume and HW registers can be updated with  original values. With that playback can be continued. So is the reason, I am reverting partial changes in the commit b1824968221c. > Please submit patches using subject lines reflecting the style for the > subsystem, this makes it easier for people to identify relevant patches. > Look at what existing commits in the area you're changing are doing and > make sure your subject lines visually resemble what they're doing. > There's no need to resubmit to fix this alone. -- Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc., is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.