diff mbox series

cpufreq: tegra194: remove opp table in exit hook

Message ID 20230809153455.29056-1-sumitg@nvidia.com
State Superseded
Headers show
Series cpufreq: tegra194: remove opp table in exit hook | expand

Commit Message

Sumit Gupta Aug. 9, 2023, 3:34 p.m. UTC
Add exit hook and remove OPP table when all the CPU's in a policy
are offlined. It will fix the below error messages when onlining
first CPU from a policy whose all CPU's were previously offlined.

 debugfs: File 'cpu5' in directory 'opp' already present!
 debugfs: File 'cpu6' in directory 'opp' already present!
 debugfs: File 'cpu7' in directory 'opp' already present!

Fixes: f41e1442ac5b ("cpufreq: tegra194: add OPP support and set bandwidth")
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
---
 drivers/cpufreq/tegra194-cpufreq.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

Comments

Sumit Gupta Aug. 25, 2023, 11:33 a.m. UTC | #1
>>>> Add exit hook and remove OPP table when all the CPU's in a policy
>>>> are offlined. It will fix the below error messages when onlining
>>>> first CPU from a policy whose all CPU's were previously offlined.
>>>>
>>>>    debugfs: File 'cpu5' in directory 'opp' already present!
>>>>    debugfs: File 'cpu6' in directory 'opp' already present!
>>>>    debugfs: File 'cpu7' in directory 'opp' already present!
>>>>
>>>> Fixes: f41e1442ac5b ("cpufreq: tegra194: add OPP support and set bandwidth")
>>>> Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
>>>> ---
>>>>    drivers/cpufreq/tegra194-cpufreq.c | 13 +++++++++++++
>>>>    1 file changed, 13 insertions(+)
>>>>
>>>> diff --git a/drivers/cpufreq/tegra194-cpufreq.c b/drivers/cpufreq/tegra194-cpufreq.c
>>>> index c90b30469165..66a9c23544db 100644
>>>> --- a/drivers/cpufreq/tegra194-cpufreq.c
>>>> +++ b/drivers/cpufreq/tegra194-cpufreq.c
>>>> @@ -454,6 +454,8 @@ static int tegra_cpufreq_init_cpufreq_table(struct cpufreq_policy *policy,
>>>>                 if (ret < 0)
>>>>                         return ret;
>>>>
>>>> +             dev_pm_opp_put(opp);
>>>> +
>>>>                 freq_table[j].driver_data = pos->driver_data;
>>>>                 freq_table[j].frequency = pos->frequency;
>>>>                 j++;
>>>> @@ -508,6 +510,16 @@ static int tegra194_cpufreq_init(struct cpufreq_policy *policy)
>>>>         return 0;
>>>>    }
>>>>
>>>> +static int tegra194_cpufreq_exit(struct cpufreq_policy *policy)
>>>> +{
>>>> +     struct device *cpu_dev = get_cpu_device(policy->cpu);
>>>> +
>>>> +     dev_pm_opp_remove_all_dynamic(cpu_dev);
>>>> +     dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);
>>>> +
>>>> +     return 0;
>>>> +}
>>>> +
>>>>    static int tegra194_cpufreq_set_target(struct cpufreq_policy *policy,
>>>>                                        unsigned int index)
>>>>    {
>>>> @@ -535,6 +547,7 @@ static struct cpufreq_driver tegra194_cpufreq_driver = {
>>>>         .target_index = tegra194_cpufreq_set_target,
>>>>         .get = tegra194_get_speed,
>>>>         .init = tegra194_cpufreq_init,
>>>> +     .exit = tegra194_cpufreq_exit,
>>>>         .attr = cpufreq_generic_attr,
>>>>    };
>>>
>>> If it is only about hotplugging of the CPUs, then you can also do this I guess.
>>>
>>> commit 263abfe74b5f ("cpufreq: dt: Implement online/offline() callbacks")
> 
> You should do this as well, this makes hotplugging paths much faster. i.e. on
> top of this patch.
> 

Sent a separate patch to add online/offline callbacks.
   https://lore.kernel.org/lkml/20230825111920.8257-1-sumitg@nvidia.com/

Also, sent v2 of this patch with updated commit description.
   https://lore.kernel.org/lkml/20230825111617.8069-1-sumitg@nvidia.com/

Thank you,
Sumit Gupta

>>> But since your driver is capable of being built as a module, I suggest you try
>>> to build it as one and insert remove it multiple times. It must cause you some
>>> trouble as you don't implement an .exit() before this patch.
>>>
>>> Eventually, I think you need to do both, what this patch and 263abfe74b5f do.
>>> Just that the reasons need to be correct for both the changes.
>>>
>>> --
>>> viresh
>>
>> Hi Viresh,
>> I got the same message on inserting and removing the module multiple times
>> as you suggested. After applying this change, the message is not coming. So,
>> the current change is resolving both scenarios as __cpufreq_offline() calls
>> either exit() or offline().
>> I can update the commit message to mention both scenarios and keep change as
>> it is?
>>
>>    cpufreq_remove_dev
>>    |-__cpufreq_offline
>>    |--tegra194_cpufreq_exit
>>
>>    cpuhp_cpufreq_offline
>>    |-__cpufreq_offline
>>    |--tegra194_cpufreq_exit
> 
> --
> viresh
diff mbox series

Patch

diff --git a/drivers/cpufreq/tegra194-cpufreq.c b/drivers/cpufreq/tegra194-cpufreq.c
index c90b30469165..66a9c23544db 100644
--- a/drivers/cpufreq/tegra194-cpufreq.c
+++ b/drivers/cpufreq/tegra194-cpufreq.c
@@ -454,6 +454,8 @@  static int tegra_cpufreq_init_cpufreq_table(struct cpufreq_policy *policy,
 		if (ret < 0)
 			return ret;
 
+		dev_pm_opp_put(opp);
+
 		freq_table[j].driver_data = pos->driver_data;
 		freq_table[j].frequency = pos->frequency;
 		j++;
@@ -508,6 +510,16 @@  static int tegra194_cpufreq_init(struct cpufreq_policy *policy)
 	return 0;
 }
 
+static int tegra194_cpufreq_exit(struct cpufreq_policy *policy)
+{
+	struct device *cpu_dev = get_cpu_device(policy->cpu);
+
+	dev_pm_opp_remove_all_dynamic(cpu_dev);
+	dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);
+
+	return 0;
+}
+
 static int tegra194_cpufreq_set_target(struct cpufreq_policy *policy,
 				       unsigned int index)
 {
@@ -535,6 +547,7 @@  static struct cpufreq_driver tegra194_cpufreq_driver = {
 	.target_index = tegra194_cpufreq_set_target,
 	.get = tegra194_get_speed,
 	.init = tegra194_cpufreq_init,
+	.exit = tegra194_cpufreq_exit,
 	.attr = cpufreq_generic_attr,
 };