lkml.org 
[lkml]   [2022]   [Jun]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v3 1/5] PM / devfreq: Fix cpufreq passive unregister erroring on PROBE_DEFER
On Wed, Jun 15, 2022 at 07:58:16AM +0900, Chanwoo Choi wrote:
> On 22. 6. 14. 20:06, Christian 'Ansuel' Marangi wrote:
> > With the passive governor, the cpu based scaling can PROBE_DEFER due to
> > the fact that CPU policy are not ready.
> > The cpufreq passive unregister notifier is called both from the
> > GOV_START errors and for the GOV_STOP and assume the notifier is
> > successfully registred every time. With GOV_START failing it's wrong to
> > loop over each possible CPU since the register path has failed for
> > some CPU policy not ready. Change the logic and unregister the notifer
> > based on the current allocated parent_cpu_data list to correctly handle
> > errors and the governor unregister path.
> >
> > Fixes: a03dacb0316f ("PM / devfreq: Add cpu based scaling support to passive governor")
> > Signed-off-by: Christian 'Ansuel' Marangi <ansuelsmth@gmail.com>
> > ---
> > drivers/devfreq/governor_passive.c | 23 ++++++-----------------
> > 1 file changed, 6 insertions(+), 17 deletions(-)
> >
> > diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c
> > index 72c67979ebe1..0188c32f5198 100644
> > --- a/drivers/devfreq/governor_passive.c
> > +++ b/drivers/devfreq/governor_passive.c
> > @@ -222,8 +222,8 @@ static int cpufreq_passive_unregister_notifier(struct devfreq *devfreq)
> > {
> > struct devfreq_passive_data *p_data
> > = (struct devfreq_passive_data *)devfreq->data;
> > - struct devfreq_cpu_data *parent_cpu_data;
> > - int cpu, ret = 0;
> > + struct devfreq_cpu_data *parent_cpu_data, *tmp;
> > + int ret;
> >
> > if (p_data->nb.notifier_call) {
> > ret = cpufreq_unregister_notifier(&p_data->nb,
> > @@ -232,27 +232,16 @@ static int cpufreq_passive_unregister_notifier(struct devfreq *devfreq)
> > return ret;
> > }
> >
> > - for_each_possible_cpu(cpu) {
> > - struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
> > - if (!policy) {
> > - ret = -EINVAL;
> > - continue;
> > - }
> > -
> > - parent_cpu_data = get_parent_cpu_data(p_data, policy);
> > - if (!parent_cpu_data) {
> > - cpufreq_cpu_put(policy);
> > - continue;
> > - }
> > -
> > + list_for_each_entry_safe(parent_cpu_data, tmp, &p_data->cpu_data_list, node) {
> > list_del(&parent_cpu_data->node);
> > +
> > if (parent_cpu_data->opp_table)
> > dev_pm_opp_put_opp_table(parent_cpu_data->opp_table);
> > +
> > kfree(parent_cpu_data);
> > - cpufreq_cpu_put(policy);
> > }
>
> I agree this patch. Just, I'd like to make the separate function
> to handle the removing of parent_cpu_data.
>
> Please add new delete_parent_cpu_data() function under get_parent_cpu_data()
> implementation and then call delete_parent_cpu_data()
> in cpufreq_passive_unregister_notifier().
>

Ok just to make sure I understand this correctly.
A dedicated function with just the list_for_each_entry_safe function
correct?

> >
> > - return ret;
> > + return 0;
> > }
> >
> > static int cpufreq_passive_register_notifier(struct devfreq *devfreq)
>
>
> --
> Best Regards,
> Samsung Electronics
> Chanwoo Choi

--
Ansuel

\
 
 \ /
  Last update: 2022-06-15 01:01    [W:0.036 / U:0.976 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site