From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Shevchenko Subject: Re: [RFC PATCH 17/40] soundwire: bus: use runtime_pm_get_sync/pm when enabled Date: Fri, 26 Jul 2019 22:08:23 +0300 Message-ID: <20190726190823.GD9224@smile.fi.intel.com> References: <20190725234032.21152-1-pierre-louis.bossart@linux.intel.com> <20190725234032.21152-18-pierre-louis.bossart@linux.intel.com> <45a912c5-134b-8642-70ef-8c1060389300@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <45a912c5-134b-8642-70ef-8c1060389300@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org To: Pierre-Louis Bossart Cc: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, tiwai@suse.de, broonie@kernel.org, vkoul@kernel.org, gregkh@linuxfoundation.org, jank@cadence.com, srinivas.kandagatla@linaro.org, slawomir.blauciak@intel.com, Sanyog Kale , "Rafael J. Wysocki" , linux-pm@vger.kernel.org List-Id: alsa-devel@alsa-project.org On Fri, Jul 26, 2019 at 01:08:57PM -0500, Pierre-Louis Bossart wrote: > This thread became unreadable with interleaved top-posting, allow me restate > the options and ask PM folks what they think > > On 7/25/19 6:40 PM, Pierre-Louis Bossart wrote: > > Not all platforms support runtime_pm for now, let's use runtime_pm > > only when enabled. Just a side note below... > > - ret = pm_runtime_get_sync(slave->bus->dev); > > - if (ret < 0) Here... > > - return ret; > > + if (pm_runtime_enabled(slave->bus->dev)) { > > + ret = pm_runtime_get_sync(slave->bus->dev); > > + if (ret < 0) ...and thus here... > > + 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); > > This is option1: we explicitly test if pm_runtime is enabled before calling > _get_sync() and _put() > > option2 (suggested by Jan Kotas): catch the -EACCESS error code > > ret = pm_runtime_get_sync(slave->bus->dev); > - if (ret < 0) > + if (ret < 0 && ret != -EACCES) ...and here, the pm_runtime_put_noidle() call is missed. > return ret; > > option3: ignore the return value as done in quite a few drivers > > Are there any other options? I am personally surprised this is not handled > in the pm_runtime core, not sure why users need to test for this? -- With Best Regards, Andy Shevchenko