From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko Subject: Re: [PATCH v4 02/24] PM / devfreq: tegra30: Keep interrupt disabled while governor is stopped Date: Tue, 16 Jul 2019 16:03:46 +0300 Message-ID: <6c517d04-cf99-f907-e74d-9fba99405a53@gmail.com> 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: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Chanwoo Choi , 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 16.07.2019 14:47, Chanwoo Choi пишет: > 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. This is necessary because this assignment is for the "governor" and not the "device". Governor is started during of devfreq_add_device(), hence there is no better way to assign device to the driver's governor. >> + >> 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. That's a good catch! Thank you very much. >> err = PTR_ERR(tegra->devfreq); > > ditto. Ok