[PATCH V4 2/2] drm/vc4: v3d: add PM suspend/resume support

[Stefan Wahren]

Hi Maíra,

Am 08.10.24 um 15:49 schrieb Maíra Canal:
> Hi Stefan,
>
> On 10/3/24 09:41, Stefan Wahren wrote:
>> Add suspend/resume support for the VC4 V3D component in order
>> to handle suspend to idle properly.
>>
>> Signed-off-by: Stefan Wahren <wahrenst at gmx.net>
>> ---
>>   drivers/gpu/drm/vc4/vc4_v3d.c | 7 +++----
>>   1 file changed, 3 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/vc4/vc4_v3d.c
>> b/drivers/gpu/drm/vc4/vc4_v3d.c
>> index 2423826c89eb..8057b06c1f16 100644
>> --- a/drivers/gpu/drm/vc4/vc4_v3d.c
>> +++ b/drivers/gpu/drm/vc4/vc4_v3d.c
>> @@ -368,7 +368,6 @@ void vc4_v3d_bin_bo_put(struct vc4_dev *vc4)
>>       mutex_unlock(&vc4->bin_bo_lock);
>>   }
>>
>> -#ifdef CONFIG_PM
>>   static int vc4_v3d_runtime_suspend(struct device *dev)
>>   {
>>       struct vc4_v3d *v3d = dev_get_drvdata(dev);
>> @@ -397,7 +396,6 @@ static int vc4_v3d_runtime_resume(struct device
>> *dev)
>>
>>       return 0;
>>   }
>> -#endif
>>
>>   int vc4_v3d_debugfs_init(struct drm_minor *minor)
>>   {
>> @@ -507,7 +505,8 @@ static void vc4_v3d_unbind(struct device *dev,
>> struct device *master,
>>   }
>>
>>   static const struct dev_pm_ops vc4_v3d_pm_ops = {
>> -    SET_RUNTIME_PM_OPS(vc4_v3d_runtime_suspend,
>> vc4_v3d_runtime_resume, NULL)
>> +    RUNTIME_PM_OPS(vc4_v3d_runtime_suspend, vc4_v3d_runtime_resume,
>> NULL)
>> +    SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
>> pm_runtime_force_resume)
>
> I have a question: How can we guarantee that no jobs are running when
> the system is forced to suspend?
Not sure what do you mean with job. userspace task or v3d job within the
driver?

Do you have something specific in mind.

Why is there a difference between runtime pm and system pm?

I must confess that i didn't test a system sleep while running a v3d
application.

Best regards
Stefan
>
> Best Regards,
> - Maíra
>
>>   };
>>
>>   static const struct component_ops vc4_v3d_ops = {
>> @@ -538,6 +537,6 @@ struct platform_driver vc4_v3d_driver = {
>>       .driver = {
>>           .name = "vc4_v3d",
>>           .of_match_table = vc4_v3d_dt_match,
>> -        .pm = &vc4_v3d_pm_ops,
>> +        .pm = pm_ptr(&vc4_v3d_pm_ops),
>>       },
>>   };
>> --
>> 2.34.1
>>