From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sameer Pujar Subject: Re: [PATCH] ALSA: hda/tegra: enable clock during probe Date: Fri, 25 Jan 2019 12:38:36 +0530 Message-ID: <4e4ef149-66b1-ce44-76a1-0221a8a7f5a7@nvidia.com> References: <1548351403-1875-1-git-send-email-spujar@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-GB Sender: linux-kernel-owner@vger.kernel.org To: Takashi Iwai Cc: pierre-louis.bossart@linux.intel.com, perex@perex.cz, alsa-devel@alsa-project.org, thierry.reding@gmail.com, jonathanh@nvidia.com, rlokhande@nvidia.com, linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org List-Id: linux-tegra@vger.kernel.org On 1/25/2019 12:38 AM, Takashi Iwai wrote: > On Thu, 24 Jan 2019 18:36:43 +0100, > Sameer Pujar wrote: >> If CONFIG_PM is disabled or runtime PM calls are forbidden, the clocks >> will not be ON. This could cause issue during probe, where hda init >> setup is done. This patch checks whether runtime PM is enabled or not. >> If disabled, clocks are enabled in probe() and disabled in remove() >> >> This patch does following minor changes as cleanup, >> * return code check for pm_runtime_get_sync() to take care of failure >> and exit gracefully. >> * In remove path runtime PM is disabled before calling snd_card_free(). >> * hda_tegra_disable_clocks() is moved out of CONFIG_PM_SLEEP check. >> * runtime PM callbacks moved out of CONFIG_PM check >> >> Signed-off-by: Sameer Pujar >> Reviewed-by: Ravindra Lokhande >> Reviewed-by: Jon Hunter > (snip) >> @@ -555,6 +553,13 @@ static int hda_tegra_probe(struct platform_device *pdev) >> if (!azx_has_pm_runtime(chip)) >> pm_runtime_forbid(hda->dev); >> >> + /* explicit resume if runtime PM is disabled */ >> + if (!pm_runtime_enabled(hda->dev)) { >> + err = hda_tegra_runtime_resume(hda->dev); >> + if (err) >> + goto out_free; >> + } >> + >> schedule_work(&hda->probe_work); > Calling runtime_resume here is really confusing... > > >> @@ -571,7 +576,14 @@ static void hda_tegra_probe_work(struct work_struct *work) >> struct platform_device *pdev = to_platform_device(hda->dev); >> int err; >> >> - pm_runtime_get_sync(hda->dev); >> + err = pm_runtime_get_sync(hda->dev); >> + if (err < 0) { >> + dev_err(hda->dev, >> + "failed in pm_runtime_get_syc with err = %d\n", >> + err); >> + return; >> + } > This pm_runtime_get_sync() is needed just because you enabled runtime > PM before probe_work. Why not deferring the runtime PM enablement > after probing done? I think what you are suggesting can be done and simplify things further. I can get rid of pm_runtime_get_sync/pm_runtime_put in probe work. > That is what we need is the hda_tegra_enable_clocks() call at probe > unconditionally before enabling runtime PM. > >> err = hda_tegra_first_init(chip, pdev); >> if (err < 0) >> goto out_free; >> @@ -599,12 +611,13 @@ static void hda_tegra_probe_work(struct work_struct *work) >> >> static int hda_tegra_remove(struct platform_device *pdev) >> { >> - int ret; >> - >> - ret = snd_card_free(dev_get_drvdata(&pdev->dev)); >> pm_runtime_disable(&pdev->dev); >> + if (!pm_runtime_status_suspended(&pdev->dev)) { >> + hda_tegra_runtime_suspend(&pdev->dev); >> + pm_runtime_set_suspended(&pdev->dev); >> + } >> - return ret; >> + return snd_card_free(dev_get_drvdata(&pdev->dev)); > > Forcing the suspend *before* snd_card_free() doesn't sound right. > It's the point before the disconnect and release procedure of all the > rest. That is, the other hardware components are still active at this > point. Ok, I will keep the sequence same and publish updated version. Thanks, Sameer. > > thanks, > > Takashi