From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko Subject: [PATCH v6 12/19] PM / devfreq: tegra30: Move clk-notifier's registration to governor's start Date: Mon, 12 Aug 2019 00:23:08 +0300 Message-ID: <20190811212315.12689-13-digetx@gmail.com> References: <20190811212315.12689-1-digetx@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190811212315.12689-1-digetx@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Thierry Reding , MyungJoo Ham , Kyungmin Park , Chanwoo Choi , 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 There is no point in receiving of the notifications while governor is stopped, let's keep them disabled like we do for the CPU freq-change notifications. This also fixes a potential use-after-free bug if notification happens after device's removal. Reviewed-by: Chanwoo Choi Signed-off-by: Dmitry Osipenko --- drivers/devfreq/tegra30-devfreq.c | 33 ++++++++++++++++++------------- 1 file changed, 19 insertions(+), 14 deletions(-) diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c index a260812f7744..bad9836b1eea 100644 --- a/drivers/devfreq/tegra30-devfreq.c +++ b/drivers/devfreq/tegra30-devfreq.c @@ -726,6 +726,19 @@ static int tegra_actmon_start(struct tegra_devfreq *tegra) actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1, ACTMON_GLB_PERIOD_CTRL); + /* + * CLK notifications are needed in order to reconfigure the upper + * consecutive watermark in accordance to the actual clock rate + * to avoid unnecessary upper interrupts. + */ + err = clk_notifier_register(tegra->emc_clock, + &tegra->clk_rate_change_nb); + if (err) { + dev_err(tegra->devfreq->dev.parent, + "Failed to register rate change notifier\n"); + return err; + } + for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) tegra_actmon_configure_device(tegra, &tegra->devices[i]); @@ -752,6 +765,8 @@ static int tegra_actmon_start(struct tegra_devfreq *tegra) for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) tegra_actmon_stop_device(&tegra->devices[i]); + clk_notifier_unregister(tegra->emc_clock, &tegra->clk_rate_change_nb); + return err; } @@ -768,6 +783,8 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra) for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) tegra_actmon_stop_device(&tegra->devices[i]); + + clk_notifier_unregister(tegra->emc_clock, &tegra->clk_rate_change_nb); } static int tegra_devfreq_target(struct device *dev, unsigned long *freq, @@ -1012,24 +1029,16 @@ static int tegra_devfreq_probe(struct platform_device *pdev) platform_set_drvdata(pdev, tegra); + tegra->clk_rate_change_nb.notifier_call = tegra_actmon_clk_notify_cb; tegra->cpu_rate_change_nb.notifier_call = tegra_actmon_cpu_notify_cb; INIT_DELAYED_WORK(&tegra->cpufreq_update_work, tegra_actmon_delayed_update); - tegra->clk_rate_change_nb.notifier_call = tegra_actmon_clk_notify_cb; - err = clk_notifier_register(tegra->emc_clock, - &tegra->clk_rate_change_nb); - if (err) { - dev_err(&pdev->dev, - "Failed to register rate change notifier\n"); - goto remove_opps; - } - err = devfreq_add_governor(&tegra_devfreq_governor); if (err) { dev_err(&pdev->dev, "Failed to add governor: %d\n", err); - goto unreg_notifier; + goto remove_opps; } tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock); @@ -1047,9 +1056,6 @@ static int tegra_devfreq_probe(struct platform_device *pdev) remove_governor: devfreq_remove_governor(&tegra_devfreq_governor); -unreg_notifier: - clk_notifier_unregister(tegra->emc_clock, &tegra->clk_rate_change_nb); - remove_opps: dev_pm_opp_remove_all_dynamic(&pdev->dev); @@ -1066,7 +1072,6 @@ static int tegra_devfreq_remove(struct platform_device *pdev) devfreq_remove_device(tegra->devfreq); devfreq_remove_governor(&tegra_devfreq_governor); - clk_notifier_unregister(tegra->emc_clock, &tegra->clk_rate_change_nb); dev_pm_opp_remove_all_dynamic(&pdev->dev); reset_control_reset(tegra->reset); -- 2.22.0