Re: [PATCH v3 13/22] ACPI: platform_profile: Require handlers to support balanced profile

[Mario Limonciello <mario.limonciello@amd.com>]

On 10/31/2024 15:39, Armin Wolf wrote:
> Am 31.10.24 um 05:09 schrieb Mario Limonciello:
> 
>> As support for multiple simultaneous platform handers is introduced it's
>> important they have at least the balanced profile in common.
>>
>> This will be used as a fallback in case setting the profile across one 
>> of the
>> handlers happens to fail.
> 
> Do we actually need this patch anymore now that we have the "custom" 
> platform profile?
> If setting the platform profile fails for some handlers, then we simply 
> display the current
> platform profile as "custom".

Yes; it's still needed because 'balanced' is used as the fallback of 
something failed.  If you fail to write to a handler it gets you back to 
a known place for all GPUs.

Now I suppose it's up for discussion if that's really the right thing to do.

Maybe because of custom we don't even need that.

If I have 3 profile handlers in
low-power
balanced
balanced

IE I'm already in 'custom'.

If I try to write performance and the first two succeed but the third 
fails what's better:

performance
performance
balanced

Or

balanced
balanced
balanced


> 
> Thanks,
> Armin Wolf
> 
>> Tested-by: Matthew Schwartz <matthew.schwartz@linux.dev>
>> Suggested-by: Hans de Goede <hdegoede@redhat.com>
>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>> ---
>>   drivers/acpi/platform_profile.c | 4 ++++
>>   1 file changed, 4 insertions(+)
>>
>> diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/ 
>> platform_profile.c
>> index b70ceb11947d0..57c66d7dbf827 100644
>> --- a/drivers/acpi/platform_profile.c
>> +++ b/drivers/acpi/platform_profile.c
>> @@ -164,6 +164,10 @@ int platform_profile_register(struct 
>> platform_profile_handler *pprof)
>>           pr_err("platform_profile: handler is invalid\n");
>>           return -EINVAL;
>>       }
>> +    if (!test_bit(PLATFORM_PROFILE_BALANCED, pprof->choices)) {
>> +        pr_err("platform_profile: handler does not support balanced 
>> profile\n");
>> +        return -EINVAL;
>> +    }
>>       if (!pprof->dev) {
>>           pr_err("platform_profile: handler device is not set\n");
>>           return -EINVAL;