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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: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Peter Geis <pgwipeout@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
This commit is contained in:
Dmitry Osipenko 2019-11-05 00:56:06 +03:00 committed by Chanwoo Choi
parent 11eb6ec5c0
commit 6f2a35d65b
1 changed files with 23 additions and 16 deletions
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39
drivers/devfreq/tegra30-devfreq.c
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@ -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);