Hi Chanwoo,
Thanks for trying to review all these patches.
On 02-12-16, 17:42, Chanwoo Choi wrote:
Hi Viresh,
On 2016년 12월 01일 19:38, Viresh Kumar wrote:
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.
Compile tested only.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org
I would like it to go via the PM tree. Perhaps that's already the default tree for this.
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 5063ac1a5939..cf14631b1945 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)
dmcfreq->rate is used on here.
Are you trying to say that dmcfreq->rate is required to have the right value as we will be using it here for comparison? If yes, then ...
Maybe struct rk3399_dmcfreq need to add the new 'curr_freq' field.
@@ -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;
This takes care of it for all cases except the first call to target()...
out: mutex_unlock(&dmcfreq->lock); return err; @@ -431,8 +429,9 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev) rcu_read_unlock(); return PTR_ERR(opp); }
- dmcfreq->rate = dev_pm_opp_get_freq(opp);
- dmcfreq->volt = dev_pm_opp_get_voltage(opp);
And this takes care of the first call to target().
Am I still missing something ?
rcu_read_unlock();
- data->curr_opp = opp;
rk3399_devfreq_dmc_profile.initial_freq = data->rate;
-- Best Regards, Chanwoo Choi