Re: [PATCH 2/8] cpufreq: Fix misplaced call to cpufreq_update_policy()

From: Viresh Kumar
Date: Fri Jul 12 2013 - 03:07:14 EST


On 12 July 2013 03:45, Srivatsa S. Bhat
<srivatsa.bhat@xxxxxxxxxxxxxxxxxx> wrote:
> The call to cpufreq_update_policy() is placed in the CPU hotplug callback
> of cpufreq_stats, which has a higher priority than the CPU hotplug callback
> of cpufreq-core. As a result, during CPU_ONLINE/CPU_ONLINE_FROZEN, we end up
> calling cpufreq_update_policy() *before* calling cpufreq_add_dev() !
> And for uninitialized CPUs, it just returns silently, not doing anything.

Hmm..

> To add to it, cpufreq_stats is not even the right place to call
> cpufreq_update_policy() to begin with. The cpufreq core ought to handle
> this in its own callback, from an elegance/relevance perspective.
>
> So move the invocation of cpufreq_update_policy() to cpufreq_cpu_callback,
> and place it *after* cpufreq_add_dev().
>
> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
> ---
>
> drivers/cpufreq/cpufreq.c | 1 +
> drivers/cpufreq/cpufreq_stats.c | 6 ------
> 2 files changed, 1 insertion(+), 6 deletions(-)
>
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index ccc6eab..f8c3100 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -1943,6 +1943,7 @@ static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb,
> case CPU_ONLINE:
> case CPU_ONLINE_FROZEN:
> cpufreq_add_dev(dev, NULL);
> + cpufreq_update_policy(cpu);

Do we need to call this for every hotplug of cpu? I am not
talking about suspend/resume here.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/