Re: [PATCH V3] drm/loongson: Create blend mode property for cursor plane

[Thomas Zimmermann <tzimmermann@suse.de>]

Am 17.09.26 um 07:08 schrieb Icenowy Zheng:
> 在 2026-09-03四的 16:42 +0800，Huacai Chen写道：
>> After commit 860e748bddcc929 ("drm: ensure blend mode supported if
>> pixel
>> format with alpha exposed") we get warnings at boot:
>>
>> loongson 0000:00:06.1: [drm] [PLANE:41:ls-cursor-plane-0] pixel
>> format with alpha exposed but blend mode not setup. Please fix.
>> loongson 0000:00:06.1: [drm] [PLANE:46:ls-cursor-plane-1] pixel
>> format with alpha exposed but blend mode not setup. Please fix.
>>
>> The reason is the cursor plane supports color formats with alpha but
>> the
>> driver doesn't create blend mode property, which triggers the warning
>> in
>> validate_blend_mode_for_alpha_formats().
>>
>> The loongson DC HW doesn't support DRM_MODE_BLEND_PREMULTI, so create
>> blend mode property with DRM_MODE_BLEND_COVERAGE for cursor planes
>> since
>> it is the only one implemented in the driver.
> It looks like this patch is hanging here for weeks. Should I apply it
> to drm-misc-fixes?

Go ahead

>
> Thanks,
> Icenowy
>
>> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
>> ---
>>   drivers/gpu/drm/loongson/lsdc_plane.c | 5 +++--
>>   1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/loongson/lsdc_plane.c
>> b/drivers/gpu/drm/loongson/lsdc_plane.c
>> index bea42215796d..bcc0ffa17bdf 100644
>> --- a/drivers/gpu/drm/loongson/lsdc_plane.c
>> +++ b/drivers/gpu/drm/loongson/lsdc_plane.c
>> @@ -7,6 +7,7 @@
>>   
>>   #include <drm/drm_atomic.h>
>>   #include <drm/drm_atomic_helper.h>
>> +#include <drm/drm_blend.h>
>>   #include <drm/drm_framebuffer.h>
>>   #include <drm/drm_gem_atomic_helper.h>
>>   #include <drm/drm_print.h>
>> @@ -765,7 +766,7 @@ int ls7a1000_cursor_plane_init(struct drm_device
>> *ddev,
>>   
>>   	drm_plane_helper_add(plane,
>> &ls7a1000_cursor_plane_helper_funcs);
>>   
>> -	return 0;
>> +	return drm_plane_create_blend_mode_property(plane,
>> BIT(DRM_MODE_BLEND_COVERAGE));
>>   }
>>   
>>   int ls7a2000_cursor_plane_init(struct drm_device *ddev,
>> @@ -790,5 +791,5 @@ int ls7a2000_cursor_plane_init(struct drm_device
>> *ddev,
>>   
>>   	drm_plane_helper_add(plane,
>> &ls7a2000_cursor_plane_helper_funcs);
>>   
>> -	return 0;
>> +	return drm_plane_create_blend_mode_property(plane,
>> BIT(DRM_MODE_BLEND_COVERAGE));
>>   }

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, (HRB 36809, AG Nürnberg)