Messages in this thread | | | Date | Wed, 15 Jun 2022 08:12:06 +0900 | Subject | Re: [PATCH v3 1/5] PM / devfreq: Fix cpufreq passive unregister erroring on PROBE_DEFER | From | Chanwoo Choi <> |
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On 22. 6. 15. 07:07, Ansuel Smith wrote: > 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?
Yes to remove the parent_cpu_data with list_for_each_entry_safe.
> >>> >>> - return ret; >>> + return 0; >>> } >>> >>> static int cpufreq_passive_register_notifier(struct devfreq *devfreq) >> >> >> -- >> Best Regards, >> Samsung Electronics >> Chanwoo Choi >
-- Best Regards, Samsung Electronics Chanwoo Choi
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