Messages in this thread | | | Date | Sat, 18 Jun 2022 03:35:08 +0900 | Subject | Re: [PATCH v4 1/4] PM / devfreq: Fix cpufreq passive unregister erroring on PROBE_DEFER | From | Chanwoo Choi <> |
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On 22. 6. 15. 18:13, Ansuel Smith wrote: > On Wed, Jun 15, 2022 at 03:48:03PM +0900, Chanwoo Choi wrote: >> On 22. 6. 15. 08:09, 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 | 39 +++++++++++++----------------- >>> 1 file changed, 17 insertions(+), 22 deletions(-) >>> >>> diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c >>> index 72c67979ebe1..95de336f20d5 100644 >>> --- a/drivers/devfreq/governor_passive.c >>> +++ b/drivers/devfreq/governor_passive.c >>> @@ -34,6 +34,20 @@ get_parent_cpu_data(struct devfreq_passive_data *p_data, >>> return NULL; >>> } >>> >>> +static void delete_parent_cpu_data(struct devfreq_passive_data *p_data) >>> +{ >>> + struct devfreq_cpu_data *parent_cpu_data, *tmp; >>> + >> >> Need to add the validation checking of argument as following: >> >> if (!p_data) >> return; >> > > Considering this is called only by cpufreq_passive_unregister_notifier > and cpufreq_passive_unregister_notifier is called only by devfreq_passive_event_handler > where the check is already done, isn't that redundant. > We should never reach delete_parent_cpu_data with no p_data. > (Unless you want to use that function somewhere else)
Actually, right as you mentioned. I'd like to check the parameter validation on each function. But, I agree to keep this path without checking p_data. If needed on later, I'll do that.
Applied it. Thanks.
> >>> + 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); >>> + } >>> +} >>> + >>> static unsigned long get_target_freq_by_required_opp(struct device *p_dev, >>> struct opp_table *p_opp_table, >>> struct opp_table *opp_table, >>> @@ -222,8 +236,7 @@ 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; >>> + int ret; >>> >>> if (p_data->nb.notifier_call) { >>> ret = cpufreq_unregister_notifier(&p_data->nb, >>> @@ -232,27 +245,9 @@ 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_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); >>> - } >>> + delete_parent_cpu_data(p_data); >>> >>> - 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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