Commit 6f2a35d6 authored by Dmitry Osipenko's avatar Dmitry Osipenko Committed by Chanwoo Choi
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PM / devfreq: tegra30: Move clk-notifier's registration to governor's start 



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: default avatarChanwoo Choi <cw00.choi@samsung.com>
Tested-by: default avatarPeter Geis <pgwipeout@gmail.com>
Signed-off-by: default avatarDmitry Osipenko <digetx@gmail.com>
Signed-off-by: default avatarChanwoo Choi <cw00.choi@samsung.com>
parent 11eb6ec5

drivers/devfreq/tegra30-devfreq.c

+23 −16
Original line number Diff line number Diff line
@@ -514,6 +514,21 @@ 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;

	}



	tegra->cur_freq = clk_get_rate(tegra->emc_clock) / KHZ;



	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++)

		tegra_actmon_configure_device(tegra, &tegra->devices[i]);
@@ -539,6 +554,8 @@ static int tegra_actmon_start(struct tegra_devfreq *tegra) 
err_stop:

	tegra_actmon_stop_devices(tegra);



	clk_notifier_unregister(tegra->emc_clock, &tegra->clk_rate_change_nb);



	return err;

}
@@ -552,6 +569,8 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra) 
	cancel_delayed_work_sync(&tegra->cpufreq_update_work);



	tegra_actmon_stop_devices(tegra);



	clk_notifier_unregister(tegra->emc_clock, &tegra->clk_rate_change_nb);

}



static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
@@ -768,7 +787,6 @@ static int tegra_devfreq_probe(struct platform_device *pdev) 
		return rate;

	}



	tegra->cur_freq = clk_get_rate(tegra->emc_clock) / KHZ;

	tegra->max_freq = rate / KHZ;



	for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++) {
@@ -796,27 +814,20 @@ 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 = tegra->cur_freq;

	tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock);

	tegra_devfreq_profile.initial_freq /= KHZ;



	devfreq = devfreq_add_device(&pdev->dev, &tegra_devfreq_profile,

				     "tegra_actmon", NULL);
@@ -830,9 +841,6 @@ 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);
@@ -849,7 +857,6 @@ 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);

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