Commit d2805601 authored by Mark Tseng's avatar Mark Tseng Committed by Chanwoo Choi
Browse files

PM / devfreq: mediatek: protect oop in critical session 

mtk_ccifreq_opp_notifier is reenter function when policy0 / policy6
change freq, so mutex_lock should protect all OPP event.

Link: https://lore.kernel.org/lkml/20230818021741.6173-1-chun-jen.tseng@mediatek.com/T/


Signed-off-by: default avatarMark Tseng <chun-jen.tseng@mediatek.com>
Signed-off-by: default avatarChanwoo Choi <cw00.choi@samsung.com>
parent 8a749fd1

drivers/devfreq/mtk-cci-devfreq.c

+3 −3
Original line number Diff line number Diff line
@@ -137,6 +137,8 @@ static int mtk_ccifreq_target(struct device *dev, unsigned long *freq, 
	if (drv->pre_freq == *freq)

		return 0;



	mutex_lock(&drv->reg_lock);



	inter_voltage = drv->inter_voltage;

	cci_pll = clk_get_parent(drv->cci_clk);
@@ -147,8 +149,6 @@ static int mtk_ccifreq_target(struct device *dev, unsigned long *freq, 
		return PTR_ERR(opp);

	}



	mutex_lock(&drv->reg_lock);



	voltage = dev_pm_opp_get_voltage(opp);

	dev_pm_opp_put(opp);
@@ -227,9 +227,9 @@ static int mtk_ccifreq_opp_notifier(struct notifier_block *nb, 
	drv = container_of(nb, struct mtk_ccifreq_drv, opp_nb);



	if (event == OPP_EVENT_ADJUST_VOLTAGE) {

		mutex_lock(&drv->reg_lock);

		freq = dev_pm_opp_get_freq(opp);



		mutex_lock(&drv->reg_lock);

		/* current opp item is changed */

		if (freq == drv->pre_freq) {

			volt = dev_pm_opp_get_voltage(opp);