On Monday, September 16, 2013 10:38:05 PM Viresh Kumar wrote: > On 16 September 2013 21:57, Jon Medhurst (Tixy) <tixy@xxxxxxxxxx> wrote: > > If I take mainline code and just change the line above to: > > You meant this line by above line? > > unlock_policy_rwsem_write(cpu); > > > up_write(&per_cpu(cpu_policy_rwsem, (per_cpu(cpufreq_cpu_data, > > cpu))->last_cpu)); > > then the big_little cpufreq driver works for me. > > That would be same as: up_write(&per_cpu(cpu_policy_rwsem, policy->last_cpu)); > > >> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > >> index 43c24aa..c18bf7b 100644 > >> --- a/drivers/cpufreq/cpufreq.c > >> +++ b/drivers/cpufreq/cpufreq.c > >> @@ -952,9 +952,16 @@ static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) > >> if (cpu == policy->cpu) > >> return; > >> > >> + /* take direct locks as lock_policy_rwsem_write wouldn't work here */ > >> + down_write(&per_cpu(cpu_policy_rwsem, policy->cpu)); > >> + down_write(&per_cpu(cpu_policy_rwsem, cpu)); > >> + > >> policy->last_cpu = policy->cpu; > >> policy->cpu = cpu; > >> > >> + up_write(&per_cpu(cpu_policy_rwsem, cpu)); > >> + up_write(&per_cpu(cpu_policy_rwsem, policy->cpu)); > > > > You've just overwritten policy->cpu with cpu. > > Stupid enough :) > > > I tried using > > policy->last_cpu to fix that, but it still doesn't work for me (giving > > the lockdep warning I mentioned.) If I change the code to just lock the > > original policy->cpu lock only, then all is fine. > > Fixed my patch now.. find attached.. Care to resend with a subject indicating that that's a patch update? Like [PATCH v2] etc. or similar? Rafael -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
