From e37d35082e75982ef714f9e25bfa43a061d0c5e6 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Mon, 5 Dec 2016 08:53:52 +0530 Subject: [PATCH] devfreq: rk3399_dmc: Don't use OPP structures outside of RCU locks The OPP structures are abused to the best here, without understanding how the OPP core and RCU locks work. In short, the OPP pointer saved in 'rk3399_dmcfreq' can become invalid under your nose, as the OPP core may free it. Fix various abuses around OPP structures and calls. Reviewed-by: Chanwoo Choi Signed-off-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- drivers/devfreq/rk3399_dmc.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/devfreq/rk3399_dmc.c b/drivers/devfreq/rk3399_dmc.c index 971ee6358456..27d2f349b53c 100644 --- a/drivers/devfreq/rk3399_dmc.c +++ b/drivers/devfreq/rk3399_dmc.c @@ -80,7 +80,6 @@ struct rk3399_dmcfreq { struct regulator *vdd_center; unsigned long rate, target_rate; unsigned long volt, target_volt; - struct dev_pm_opp *curr_opp; }; static int rk3399_dmcfreq_target(struct device *dev, unsigned long *freq, @@ -102,9 +101,6 @@ static int rk3399_dmcfreq_target(struct device *dev, unsigned long *freq, target_rate = dev_pm_opp_get_freq(opp); target_volt = dev_pm_opp_get_voltage(opp); - dmcfreq->rate = dev_pm_opp_get_freq(dmcfreq->curr_opp); - dmcfreq->volt = dev_pm_opp_get_voltage(dmcfreq->curr_opp); - rcu_read_unlock(); if (dmcfreq->rate == target_rate) @@ -165,7 +161,9 @@ static int rk3399_dmcfreq_target(struct device *dev, unsigned long *freq, if (err) dev_err(dev, "Cannot to set vol %lu uV\n", target_volt); - dmcfreq->curr_opp = opp; + dmcfreq->rate = target_rate; + dmcfreq->volt = target_volt; + out: mutex_unlock(&dmcfreq->lock); return err; @@ -430,8 +428,9 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev) rcu_read_unlock(); return PTR_ERR(opp); } + data->rate = dev_pm_opp_get_freq(opp); + data->volt = dev_pm_opp_get_voltage(opp); rcu_read_unlock(); - data->curr_opp = opp; rk3399_devfreq_dmc_profile.initial_freq = data->rate;