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authorDmitry Osipenko <digetx@gmail.com>2019-11-05 00:56:06 +0300
committerChanwoo Choi <cw00.choi@samsung.com>2019-11-06 06:04:00 +0300
commit6f2a35d65b3c4bbc579a115589edcc7ed6239dce (patch)
tree76cb248ef16c8cd470e7bb2c87cad4d4f1452e81 /drivers/devfreq
parent11eb6ec5c0d4ad513c62e33009bcb15d84dfff56 (diff)
downloadlinux-6f2a35d65b3c4bbc579a115589edcc7ed6239dce.tar.xz
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>
Diffstat (limited to 'drivers/devfreq')
-rw-r--r--drivers/devfreq/tegra30-devfreq.c39
1 files changed, 23 insertions, 16 deletions
diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
index 2d720e7e2236..6960d8ba0577 100644
--- a/drivers/devfreq/tegra30-devfreq.c
+++ b/drivers/devfreq/tegra30-devfreq.c
@@ -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);