[PATCH] drm/amd/display: Guard ACPI calls with CONFIG_ACPI

[Leo Li]

On 2024-06-10 11:32, Mario Limonciello wrote:
> On 6/10/2024 09:55, sunpeng.li at amd.com wrote:
>> From: Leo Li <sunpeng.li at amd.com>
>>
>> To fix CONFIG_ACPI disabled build error.
>>
>> Fixes: ec6f30c776ad ("drm/amd/display: Set default brightness according to ACPI")
>> Signed-off-by: Leo Li <sunpeng.li at amd.com>
>> ---
>>   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 6 ++++++
>>   1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c 
>> b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> index a2c098f1b07c..6b3634db4c15 100644
>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> @@ -4572,7 +4572,9 @@ amdgpu_dm_register_backlight_device(struct 
>> amdgpu_dm_connector *aconnector)
>>       struct drm_device *drm = aconnector->base.dev;
>>       struct amdgpu_display_manager *dm = &drm_to_adev(drm)->dm;
>>       struct backlight_properties props = { 0 };
>> +#if defined(CONFIG_ACPI)
>>       struct amdgpu_dm_backlight_caps caps = { 0 };
>> +#endif
>>       char bl_name[16];
>>       if (aconnector->bl_idx == -1)
>> @@ -4585,6 +4587,7 @@ amdgpu_dm_register_backlight_device(struct 
>> amdgpu_dm_connector *aconnector)
>>           return;
>>       }
>> +#if defined(CONFIG_ACPI)
>>       amdgpu_acpi_get_backlight_caps(&caps);
>>       if (caps.caps_valid) {
>>           if (power_supply_is_system_supplied() > 0)
>> @@ -4593,6 +4596,9 @@ amdgpu_dm_register_backlight_device(struct 
>> amdgpu_dm_connector *aconnector)
>>               props.brightness = caps.dc_level;
>>       } else
>>           props.brightness = AMDGPU_MAX_BL_LEVEL;
>> +#else
>> +    props.brightness = AMDGPU_MAX_BL_LEVEL;
>> +#endif
> 
> Hey Leo,
> 
> Thanks for the patch!
> 
> As caps is initialized to {0} caps.caps_valid will be invalid.  So I see two 
> other ways to solve this that are a little cleaner (IMO):
> 
> 1)  Just block the one call:
> 
> #if defined(CONFIG_ACPI)
>      amdgpu_acpi_get_backlight_caps(&caps);
> #endif
> 
> 2) Add a stub inline no-op function for amdgpu_acpi_get_backlight_caps() to the 
> header.
> 
> I personally think #2 is cleaner (less ifdef makes a lot more readable code).

Agreed, we're using #2 for other ACPI stuff, actually.
Sending v2 soon.

- Leo
> 
>>       props.max_brightness = AMDGPU_MAX_BL_LEVEL;
>>       props.type = BACKLIGHT_RAW;