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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 448A6C7618B for ; Fri, 26 Jul 2019 08:42:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 177CF2166E for ; Fri, 26 Jul 2019 08:42:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726636AbfGZImp (ORCPT ); Fri, 26 Jul 2019 04:42:45 -0400 Received: from mga07.intel.com ([134.134.136.100]:46047 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725928AbfGZImp (ORCPT ); Fri, 26 Jul 2019 04:42:45 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Jul 2019 01:42:44 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,310,1559545200"; d="scan'208";a="321983090" Received: from gliakhov-mobl2.ger.corp.intel.com (HELO ubuntu) ([10.249.35.244]) by orsmga004.jf.intel.com with ESMTP; 26 Jul 2019 01:42:41 -0700 Date: Fri, 26 Jul 2019 10:42:40 +0200 From: Guennadi Liakhovetski To: Jan Kotas Cc: "alsa-devel@alsa-project.org" , "tiwai@suse.de" , "gregkh@linuxfoundation.org" , Pierre-Louis Bossart , LKML , Vinod Koul , Mark Brown , Srinivas Kandagatla , "slawomir.blauciak@intel.com" , Sanyog Kale Subject: Re: [alsa-devel] [RFC PATCH 17/40] soundwire: bus: use runtime_pm_get_sync/pm when enabled Message-ID: <20190726084239.GG16003@ubuntu> References: <20190725234032.21152-1-pierre-louis.bossart@linux.intel.com> <20190725234032.21152-18-pierre-louis.bossart@linux.intel.com> <20190726073931.GE16003@ubuntu> <716D5D19-D494-4F4E-9180-24CB5A575648@global.cadence.com> <20190726082258.GF16003@ubuntu> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 26, 2019 at 08:33:35AM +0000, Jan Kotas wrote: > > > > On 26 Jul 2019, at 10:22, Guennadi Liakhovetski wrote: > > > > EXTERNAL MAIL > > > > > > Hi Jan, > > > > On Fri, Jul 26, 2019 at 07:47:04AM +0000, Jan Kotas wrote: > >> Hello, > >> > >> I while back I proposed a patch for this, but it went nowhere. > >> > >> https://urldefense.proofpoint.com/v2/url?u=https-3A__patchwork.kernel.org_patch_10887405_&d=DwIBAg&c=aUq983L2pue2FqKFoP6PGHMJQyoJ7kl3s3GZ-_haXqY&r=g7GAQENVXx_RQdyXHInPMg&m=i_0S359hFIVqNgv3fR5_MNzDOHP99trdXszZ-FMiQEE&s=ddktFZYlePh-bC7kXeoKWt4QomupzHATK4FLY4oSWKA&e= > >> Maybe something similar can be implemented? > > > > Yes, I was thinking about checkint -EACCESS too, but then I noticed this code > > in rpm_resume(): > > > > else if (dev->power.disable_depth == 1 && dev->power.is_suspended > > && dev->power.runtime_status == RPM_ACTIVE) > > retval = 1; > > > > i.e. if RT-PM is disabled on the device (but only exactly once?..) and it's > > active and the device is suspended for a system suspend, the function will > > return 1. I don't understand the logic of this code, but it seems to me it > > could break the -EACCESS check? > > > > Hi, > > In such case ret < 0 will not be true, which I think is fine, > if I’m understanding you correctly. Yes, if we just have to distinguish a single case "RT-PM is enabled and it failed." Which is indeed the case here, it seems. However if we want to check whether RT-PM is disabled after a call to, say, pm_runtime_get_sync(), then just checking -EACCESS isn't always enough - there can be cases when RT-PM is disabled and the return code is 1. But yes, just for checking for failures, like here, it should be fine. Thanks Guennadi > >> Jan > >> > >>> On 26 Jul 2019, at 09:39, Guennadi Liakhovetski wrote: > >>> > >>> EXTERNAL MAIL > >>> > >>> > >>> Hi Pierre, > >>> > >>> I might be wrong but this doesn't seem right to me. (Supposedly) all RT-PM > >>> functions check for "enabled" internally. The only thing that can happen is > >>> that if RT-PM isn't enabled some of those functions will return an error. > >>> So, in those cases where the return value of RT-PM functions isn't checked, > >>> I don't think you need to do anything. Where it is checked maybe do > >>> > >>> + if (ret < 0 && pm_runtime_enabled(slave->bus->dev)) > >>> > >>> Thanks > >>> Guennadi > >>> > >>> On Thu, Jul 25, 2019 at 06:40:09PM -0500, Pierre-Louis Bossart wrote: > >>>> Not all platforms support runtime_pm for now, let's use runtime_pm > >>>> only when enabled. > >>>> > >>>> Suggested-by: Srinivas Kandagatla > >>>> Signed-off-by: Pierre-Louis Bossart > >>>> --- > >>>> drivers/soundwire/bus.c | 25 ++++++++++++++++--------- > >>>> 1 file changed, 16 insertions(+), 9 deletions(-) > >>>> > >>>> diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c > >>>> index 5ad4109dc72f..0a45dc5713df 100644 > >>>> --- a/drivers/soundwire/bus.c > >>>> +++ b/drivers/soundwire/bus.c > >>>> @@ -332,12 +332,16 @@ int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val) > >>>> if (ret < 0) > >>>> return ret; > >>>> > >>>> - ret = pm_runtime_get_sync(slave->bus->dev); > >>>> - if (ret < 0) > >>>> - return ret; > >>>> + if (pm_runtime_enabled(slave->bus->dev)) { > >>>> + ret = pm_runtime_get_sync(slave->bus->dev); > >>>> + if (ret < 0) > >>>> + return ret; > >>>> + } > >>>> > >>>> ret = sdw_transfer(slave->bus, &msg); > >>>> - pm_runtime_put(slave->bus->dev); > >>>> + > >>>> + if (pm_runtime_enabled(slave->bus->dev)) > >>>> + pm_runtime_put(slave->bus->dev); > >>>> > >>>> return ret; > >>>> } > >>>> @@ -359,13 +363,16 @@ int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val) > >>>> slave->dev_num, SDW_MSG_FLAG_WRITE, val); > >>>> if (ret < 0) > >>>> return ret; > >>>> - > >>>> - ret = pm_runtime_get_sync(slave->bus->dev); > >>>> - if (ret < 0) > >>>> - return ret; > >>>> + if (pm_runtime_enabled(slave->bus->dev)) { > >>>> + ret = pm_runtime_get_sync(slave->bus->dev); > >>>> + if (ret < 0) > >>>> + return ret; > >>>> + } > >>>> > >>>> ret = sdw_transfer(slave->bus, &msg); > >>>> - pm_runtime_put(slave->bus->dev); > >>>> + > >>>> + if (pm_runtime_enabled(slave->bus->dev)) > >>>> + pm_runtime_put(slave->bus->dev); > >>>> > >>>> return ret; > >>>> } > >>>> -- > >>>> 2.20.1 > >>>> > >>>> _______________________________________________ > >>>> Alsa-devel mailing list > >>>> Alsa-devel@alsa-project.org > >>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__mailman.alsa-2Dproject.org_mailman_listinfo_alsa-2Ddevel&d=DwIBAg&c=aUq983L2pue2FqKFoP6PGHMJQyoJ7kl3s3GZ-_haXqY&r=g7GAQENVXx_RQdyXHInPMg&m=vETGQLSPeGb7K_ZsXv4Tl3VFfdXzyummTDga97ozJcg&s=LiW4SToh5U0zhnkox54oRhJ1u3vFNbBB9nmzRDuCDjI&e= > >> > >> _______________________________________________ > >> Alsa-devel mailing list > >> Alsa-devel@alsa-project.org > >> https://urldefense.proofpoint.com/v2/url?u=https-3A__mailman.alsa-2Dproject.org_mailman_listinfo_alsa-2Ddevel&d=DwIBAg&c=aUq983L2pue2FqKFoP6PGHMJQyoJ7kl3s3GZ-_haXqY&r=g7GAQENVXx_RQdyXHInPMg&m=i_0S359hFIVqNgv3fR5_MNzDOHP99trdXszZ-FMiQEE&s=RxPHxKfI3v6Fkh7qzKjq8sNi-5QMoY8XfyMDSquA38o&e= > > _______________________________________________ > Alsa-devel mailing list > Alsa-devel@alsa-project.org > https://mailman.alsa-project.org/mailman/listinfo/alsa-devel