From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chanwoo Choi Subject: Re: [PATCH v4 02/24] PM / devfreq: tegra30: Keep interrupt disabled while governor is stopped Date: Tue, 16 Jul 2019 20:47:05 +0900 Message-ID: References: <20190707223303.6755-1-digetx@gmail.com> <20190707223303.6755-3-digetx@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190707223303.6755-3-digetx@gmail.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Dmitry Osipenko , Thierry Reding , MyungJoo Ham , Kyungmin Park , Jonathan Hunter , Tomeu Vizoso Cc: linux-pm@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-tegra@vger.kernel.org On 19. 7. 8. 오전 7:32, Dmitry Osipenko wrote: > There is no real need to keep interrupt always-enabled, will be nicer > to keep it disabled while governor is inactive. > > Suggested-by: Thierry Reding > Signed-off-by: Dmitry Osipenko > --- > drivers/devfreq/tegra30-devfreq.c | 43 ++++++++++++++++--------------- > 1 file changed, 22 insertions(+), 21 deletions(-) > > diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c > index a27300f40b0b..5e2b133babdd 100644 > --- a/drivers/devfreq/tegra30-devfreq.c > +++ b/drivers/devfreq/tegra30-devfreq.c > @@ -11,6 +11,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -416,8 +417,6 @@ static void tegra_actmon_start(struct tegra_devfreq *tegra) > { > unsigned int i; > > - disable_irq(tegra->irq); > - > actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1, > ACTMON_GLB_PERIOD_CTRL); > > @@ -442,8 +441,6 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra) > } > > actmon_write_barrier(tegra); > - > - enable_irq(tegra->irq); > } > > static int tegra_devfreq_target(struct device *dev, unsigned long *freq, > @@ -552,6 +549,12 @@ static int tegra_governor_event_handler(struct devfreq *devfreq, > { > struct tegra_devfreq *tegra = dev_get_drvdata(devfreq->dev.parent); > > + /* > + * Couple device with the governor early as it is needed at > + * the moment of governor's start (used by ISR). > + */ > + tegra->devfreq = devfreq; I'm not sure it is necessary. Almost devfreq device get the devfreq instance on probe timing through devfreq_add_device directly. > + > switch (event) { > case DEVFREQ_GOV_START: > devfreq_monitor_start(devfreq); > @@ -586,10 +589,11 @@ static struct devfreq_governor tegra_devfreq_governor = { > > static int tegra_devfreq_probe(struct platform_device *pdev) > { > - struct tegra_devfreq *tegra; > struct tegra_devfreq_device *dev; > - unsigned int i; > + struct tegra_devfreq *tegra; > + struct devfreq *devfreq; > unsigned long rate; > + unsigned int i; > int err; > > tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL); > @@ -625,6 +629,16 @@ static int tegra_devfreq_probe(struct platform_device *pdev) > } > tegra->irq = err; > > + irq_set_status_flags(tegra->irq, IRQ_NOAUTOEN); > + > + err = devm_request_threaded_irq(&pdev->dev, tegra->irq, NULL, > + actmon_thread_isr, IRQF_ONESHOT, > + "tegra-devfreq", tegra); > + if (err) { > + dev_err(&pdev->dev, "Interrupt request failed: %d\n", err); > + return err; > + } > + > reset_control_assert(tegra->reset); > > err = clk_prepare_enable(tegra->clock); > @@ -672,28 +686,15 @@ static int tegra_devfreq_probe(struct platform_device *pdev) > } > > tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock); > - tegra->devfreq = devfreq_add_device(&pdev->dev, > - &tegra_devfreq_profile, > - "tegra_actmon", > - NULL); > + devfreq = devfreq_add_device(&pdev->dev, &tegra_devfreq_profile, > + "tegra_actmon", NULL); > if (IS_ERR(tegra->devfreq)) { Have to check 'devfreq' instead of 'tegra->devfreq'. Did you test it? It might be failed because 'tegra->devfreq is NULL. > err = PTR_ERR(tegra->devfreq); ditto. > goto remove_governor; > } > > - err = devm_request_threaded_irq(&pdev->dev, tegra->irq, NULL, > - actmon_thread_isr, IRQF_ONESHOT, > - "tegra-devfreq", tegra); > - if (err) { > - dev_err(&pdev->dev, "Interrupt request failed: %d\n", err); > - goto remove_devfreq; > - } > - > return 0; > > -remove_devfreq: > - devfreq_remove_device(tegra->devfreq); > - > remove_governor: > devfreq_remove_governor(&tegra_devfreq_governor); > > -- Best Regards, Chanwoo Choi Samsung Electronics