From d2805601988fb0b41247c95dcb4b8b8455921978 Mon Sep 17 00:00:00 2001 From: Mark Tseng Date: Fri, 18 Aug 2023 10:17:41 +0800 Subject: [PATCH] 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: Mark Tseng Signed-off-by: Chanwoo Choi --- drivers/devfreq/mtk-cci-devfreq.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/devfreq/mtk-cci-devfreq.c b/drivers/devfreq/mtk-cci-devfreq.c index 83a73f0ccd80..b0ed25e33f2b 100644 --- a/drivers/devfreq/mtk-cci-devfreq.c +++ b/drivers/devfreq/mtk-cci-devfreq.c @@ -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);