Messages in this thread | | | Date | Fri, 20 Sep 2013 17:36:37 +0200 | Subject | Re: Regression on cpufreq in v3.12-rc1 | From | Linus Walleij <> |
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On Fri, Sep 20, 2013 at 11:35 AM, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> commit 389fbc3c8ad7c339cd2d9572d73c355b7b967823 > Author: Viresh Kumar <viresh.kumar@linaro.org> > Date: Fri Sep 20 14:55:31 2013 +0530 > > cpufreq: check cpufreq driver is valid and cpufreq isn't disabled > in cpufreq_get() > > cpufreq_get() can be called from external drivers which might not > be aware if > cpufreq driver is registered or not. And so we should actually > check if cpufreq > driver is registered or not and also if cpufreq is active or > disabled, at the > beginning of cpufreq_get(). > > Otherwise call to lock_policy_rwsem_read() might hit BUG_ON(!policy). > > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > --- > drivers/cpufreq/cpufreq.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > index 82ecbe3..db004a8 100644 > --- a/drivers/cpufreq/cpufreq.c > +++ b/drivers/cpufreq/cpufreq.c > @@ -1460,6 +1460,9 @@ unsigned int cpufreq_get(unsigned int cpu) > { > unsigned int ret_freq = 0; > > + if (cpufreq_disabled() || !cpufreq_driver) > + return -ENOENT; > + > if (!down_read_trylock(&cpufreq_rwsem)) > return 0;
This works! My system boots without crashes after this.
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Yours, Linus Walleij
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