[PATCH 1/2] drm/verisilicon: set blend mode for the primary plane

[PATCH 1/2] drm/verisilicon: set blend mode for the primary plane

[Icenowy Zheng]

Blend modes are now required to expose pixel formats w/ alpha.

As it's the primary plane and blending is explicitly disabled, just
expose PIXEL_NONE blend mode.

Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
---
 drivers/gpu/drm/verisilicon/vs_primary_plane.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/verisilicon/vs_primary_plane.c b/drivers/gpu/drm/verisilicon/vs_primary_plane.c
index 1f2be41ae496c..8d58682d88ef8 100644
--- a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
+++ b/drivers/gpu/drm/verisilicon/vs_primary_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_crtc.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_framebuffer.h>
@@ -179,5 +180,7 @@ struct drm_plane *vs_primary_plane_init(struct drm_device *drm_dev, struct vs_dc
 
 	drm_plane_helper_add(plane, &vs_primary_plane_helper_funcs);
 
+	drm_plane_create_blend_mode_property(plane,
+					     BIT(DRM_MODE_BLEND_PIXEL_NONE));
 	return plane;
 }
-- 
2.52.0

[PATCH 2/2] drm/verisilicon: set blend mode for the cursor plane

[Icenowy Zheng]

Blend mode properties are now required to expose pixel formats w/ alpha.

Experiments show that the fixed blending mode for the cursor seems to be
COVERAGE:

- With a cursor plane filled with R=G=0, B=0xff, A=0x40, the cursor is
  visible on a pure-white background, which means the background is
  multiplied.
- With a cursor plane filled with R=G=B=0xff, A=0x40, the cursor isn't
  pure white and non-white patterns can be see through, which means the
  cursor is multiplied.

Add a fixed COVERAGE blend mode property for the cursor plane.

Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
---
 drivers/gpu/drm/verisilicon/vs_cursor_plane.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/verisilicon/vs_cursor_plane.c b/drivers/gpu/drm/verisilicon/vs_cursor_plane.c
index fa4f601dd0c87..36e3664373fa1 100644
--- a/drivers/gpu/drm/verisilicon/vs_cursor_plane.c
+++ b/drivers/gpu/drm/verisilicon/vs_cursor_plane.c
@@ -11,6 +11,7 @@
 
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
+#include <drm/drm_blend.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_framebuffer.h>
@@ -268,5 +269,7 @@ struct drm_plane *vs_cursor_plane_init(struct drm_device *drm_dev,
 
 	drm_plane_helper_add(plane, &vs_cursor_plane_helper_funcs);
 
+	drm_plane_create_blend_mode_property(plane,
+					     BIT(DRM_MODE_BLEND_COVERAGE));
 	return plane;
 }
-- 
2.52.0

Re: [PATCH 2/2] drm/verisilicon: set blend mode for the cursor plane

[Thomas Zimmermann]

Am 01.09.26 um 19:17 schrieb Icenowy Zheng:
> Blend mode properties are now required to expose pixel formats w/ alpha.
>
> Experiments show that the fixed blending mode for the cursor seems to be
> COVERAGE:
>
> - With a cursor plane filled with R=G=0, B=0xff, A=0x40, the cursor is
>    visible on a pure-white background, which means the background is
>    multiplied.
> - With a cursor plane filled with R=G=B=0xff, A=0x40, the cursor isn't
>    pure white and non-white patterns can be see through, which means the
>    cursor is multiplied.
>
> Add a fixed COVERAGE blend mode property for the cursor plane.
>
> Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
> ---
>   drivers/gpu/drm/verisilicon/vs_cursor_plane.c | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/verisilicon/vs_cursor_plane.c b/drivers/gpu/drm/verisilicon/vs_cursor_plane.c
> index fa4f601dd0c87..36e3664373fa1 100644
> --- a/drivers/gpu/drm/verisilicon/vs_cursor_plane.c
> +++ b/drivers/gpu/drm/verisilicon/vs_cursor_plane.c
> @@ -11,6 +11,7 @@
>   
>   #include <drm/drm_atomic.h>
>   #include <drm/drm_atomic_helper.h>
> +#include <drm/drm_blend.h>
>   #include <drm/drm_crtc.h>
>   #include <drm/drm_fourcc.h>
>   #include <drm/drm_framebuffer.h>
> @@ -268,5 +269,7 @@ struct drm_plane *vs_cursor_plane_init(struct drm_device *drm_dev,
>   
>   	drm_plane_helper_add(plane, &vs_cursor_plane_helper_funcs);
>   
> +	drm_plane_create_blend_mode_property(plane,
> +					     BIT(DRM_MODE_BLEND_COVERAGE));

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>

Please see the other patch for my comments on coding style.

>   	return plane;
>   }

-- 
--
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)

Re: [PATCH 1/2] drm/verisilicon: set blend mode for the primary plane

[Icenowy Zheng]

在 2026-09-02三的 01:17 +0800，Icenowy Zheng写道：
> Blend modes are now required to expose pixel formats w/ alpha.
> 
> As it's the primary plane and blending is explicitly disabled, just
> expose PIXEL_NONE blend mode.

Gently ping for reviews.

Thanks,
Icenowy

> 
> Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
> ---
>  drivers/gpu/drm/verisilicon/vs_primary_plane.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> b/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> index 1f2be41ae496c..8d58682d88ef8 100644
> --- a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> +++ b/drivers/gpu/drm/verisilicon/vs_primary_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_crtc.h>
>  #include <drm/drm_fourcc.h>
>  #include <drm/drm_framebuffer.h>
> @@ -179,5 +180,7 @@ struct drm_plane *vs_primary_plane_init(struct
> drm_device *drm_dev, struct vs_dc
>  
>  	drm_plane_helper_add(plane, &vs_primary_plane_helper_funcs);
>  
> +	drm_plane_create_blend_mode_property(plane,
> +					    
> BIT(DRM_MODE_BLEND_PIXEL_NONE));
>  	return plane;
>  }

Re: [PATCH 1/2] drm/verisilicon: set blend mode for the primary plane

[Thomas Zimmermann]

Hi

Am 10.09.26 um 09:09 schrieb Icenowy Zheng:
> 在 2026-09-02三的 01:17 +0800，Icenowy Zheng写道：
>> Blend modes are now required to expose pixel formats w/ alpha.
>>
>> As it's the primary plane and blending is explicitly disabled, just
>> expose PIXEL_NONE blend mode.
> Gently ping for reviews.

What do these alpha formats do?  Are they a hardware feature?  It looks 
like they are programmable, but don't differ from XRGB at all.

Best regards
Thomas

>
> Thanks,
> Icenowy
>
>> Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
>> ---
>>   drivers/gpu/drm/verisilicon/vs_primary_plane.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
>> b/drivers/gpu/drm/verisilicon/vs_primary_plane.c
>> index 1f2be41ae496c..8d58682d88ef8 100644
>> --- a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
>> +++ b/drivers/gpu/drm/verisilicon/vs_primary_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_crtc.h>
>>   #include <drm/drm_fourcc.h>
>>   #include <drm/drm_framebuffer.h>
>> @@ -179,5 +180,7 @@ struct drm_plane *vs_primary_plane_init(struct
>> drm_device *drm_dev, struct vs_dc
>>   
>>   	drm_plane_helper_add(plane, &vs_primary_plane_helper_funcs);
>>   
>> +	drm_plane_create_blend_mode_property(plane,
>> +					
>> BIT(DRM_MODE_BLEND_PIXEL_NONE));
>>   	return plane;
>>   }

-- 
--
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)

Re: [PATCH 1/2] drm/verisilicon: set blend mode for the primary plane

[Icenowy Zheng]

在 2026-09-10四的 09:58 +0200，Thomas Zimmermann写道：
> Hi
> 
> Am 10.09.26 um 09:09 schrieb Icenowy Zheng:
> > 在 2026-09-02三的 01:17 +0800，Icenowy Zheng写道：
> > > Blend modes are now required to expose pixel formats w/ alpha.
> > > 
> > > As it's the primary plane and blending is explicitly disabled,
> > > just
> > > expose PIXEL_NONE blend mode.
> > Gently ping for reviews.
> 
> What do these alpha formats do?  Are they a hardware feature?  It
> looks 
> like they are programmable, but don't differ from XRGB at all.

I think they're for consistency with overlay planes.

Thanks,
Icenowy

> 
> Best regards
> Thomas
> 
> > 
> > Thanks,
> > Icenowy
> > 
> > > Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
> > > ---
> > >   drivers/gpu/drm/verisilicon/vs_primary_plane.c | 3 +++
> > >   1 file changed, 3 insertions(+)
> > > 
> > > diff --git a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> > > b/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> > > index 1f2be41ae496c..8d58682d88ef8 100644
> > > --- a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> > > +++ b/drivers/gpu/drm/verisilicon/vs_primary_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_crtc.h>
> > >   #include <drm/drm_fourcc.h>
> > >   #include <drm/drm_framebuffer.h>
> > > @@ -179,5 +180,7 @@ struct drm_plane
> > > *vs_primary_plane_init(struct
> > > drm_device *drm_dev, struct vs_dc
> > >   
> > >   	drm_plane_helper_add(plane,
> > > &vs_primary_plane_helper_funcs);
> > >   
> > > +	drm_plane_create_blend_mode_property(plane,
> > > +					
> > > BIT(DRM_MODE_BLEND_PIXEL_NONE));
> > >   	return plane;
> > >   }

Re: [PATCH 1/2] drm/verisilicon: set blend mode for the primary plane

[Thomas Zimmermann]

Hi

Am 10.09.26 um 10:00 schrieb Icenowy Zheng:
> 在 2026-09-10四的 09:58 +0200，Thomas Zimmermann写道：
>> Hi
>>
>> Am 10.09.26 um 09:09 schrieb Icenowy Zheng:
>>> 在 2026-09-02三的 01:17 +0800，Icenowy Zheng写道：
>>>> Blend modes are now required to expose pixel formats w/ alpha.
>>>>
>>>> As it's the primary plane and blending is explicitly disabled,
>>>> just
>>>> expose PIXEL_NONE blend mode.
>>> Gently ping for reviews.
>> What do these alpha formats do?  Are they a hardware feature?  It
>> looks
>> like they are programmable, but don't differ from XRGB at all.
> I think they're for consistency with overlay planes.

But there are no overlay planes in this driver, are there?

What I want to get at is that it might be preferable to remove ARGB 
entirely from the primary plane if it does not to serve a purpose. But 
if the driver can do something useful with these formats, it might be 
worth exposing that instead.

In pl111, we now remove the ARGB foramts because the hardware does not 
handle them at all. The situation seems less clear in verisilicon.

Best regards
Thomas


>
> Thanks,
> Icenowy
>
>> Best regards
>> Thomas
>>
>>> Thanks,
>>> Icenowy
>>>
>>>> Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
>>>> ---
>>>>    drivers/gpu/drm/verisilicon/vs_primary_plane.c | 3 +++
>>>>    1 file changed, 3 insertions(+)
>>>>
>>>> diff --git a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
>>>> b/drivers/gpu/drm/verisilicon/vs_primary_plane.c
>>>> index 1f2be41ae496c..8d58682d88ef8 100644
>>>> --- a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
>>>> +++ b/drivers/gpu/drm/verisilicon/vs_primary_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_crtc.h>
>>>>    #include <drm/drm_fourcc.h>
>>>>    #include <drm/drm_framebuffer.h>
>>>> @@ -179,5 +180,7 @@ struct drm_plane
>>>> *vs_primary_plane_init(struct
>>>> drm_device *drm_dev, struct vs_dc
>>>>    
>>>>    	drm_plane_helper_add(plane,
>>>> &vs_primary_plane_helper_funcs);
>>>>    
>>>> +	drm_plane_create_blend_mode_property(plane,
>>>> +					
>>>> BIT(DRM_MODE_BLEND_PIXEL_NONE));
>>>>    	return plane;
>>>>    }

-- 
--
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)

Re: [PATCH 1/2] drm/verisilicon: set blend mode for the primary plane

[Icenowy Zheng]

在 2026-09-10四的 10:31 +0200，Thomas Zimmermann写道：
> Hi
> 
> Am 10.09.26 um 10:00 schrieb Icenowy Zheng:
> > 在 2026-09-10四的 09:58 +0200，Thomas Zimmermann写道：
> > > Hi
> > > 
> > > Am 10.09.26 um 09:09 schrieb Icenowy Zheng:
> > > > 在 2026-09-02三的 01:17 +0800，Icenowy Zheng写道：
> > > > > Blend modes are now required to expose pixel formats w/
> > > > > alpha.
> > > > > 
> > > > > As it's the primary plane and blending is explicitly
> > > > > disabled,
> > > > > just
> > > > > expose PIXEL_NONE blend mode.
> > > > Gently ping for reviews.
> > > What do these alpha formats do?  Are they a hardware feature?  It
> > > looks
> > > like they are programmable, but don't differ from XRGB at all.
> > I think they're for consistency with overlay planes.
> 
> But there are no overlay planes in this driver, are there?
> 
> What I want to get at is that it might be preferable to remove ARGB 
> entirely from the primary plane if it does not to serve a purpose.
> But 
> if the driver can do something useful with these formats, it might be
> worth exposing that instead.

The device has overlay planes, but they're currently not supported.

The manual for MA35D1 does list formats with alpha for
DcregFrameBufferConfig0 register, and the hardware can properly handle
these format values (by ignoring the A bits).

Thanks,
Icenowy
> 
> In pl111, we now remove the ARGB foramts because the hardware does
> not 
> handle them at all. The situation seems less clear in verisilicon.
> 
> Best regards
> Thomas
> 
> 
> > 
> > Thanks,
> > Icenowy
> > 
> > > Best regards
> > > Thomas
> > > 
> > > > Thanks,
> > > > Icenowy
> > > > 
> > > > > Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
> > > > > ---
> > > > >    drivers/gpu/drm/verisilicon/vs_primary_plane.c | 3 +++
> > > > >    1 file changed, 3 insertions(+)
> > > > > 
> > > > > diff --git a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> > > > > b/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> > > > > index 1f2be41ae496c..8d58682d88ef8 100644
> > > > > --- a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> > > > > +++ b/drivers/gpu/drm/verisilicon/vs_primary_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_crtc.h>
> > > > >    #include <drm/drm_fourcc.h>
> > > > >    #include <drm/drm_framebuffer.h>
> > > > > @@ -179,5 +180,7 @@ struct drm_plane
> > > > > *vs_primary_plane_init(struct
> > > > > drm_device *drm_dev, struct vs_dc
> > > > >    
> > > > >    	drm_plane_helper_add(plane,
> > > > > &vs_primary_plane_helper_funcs);
> > > > >    
> > > > > +	drm_plane_create_blend_mode_property(plane,
> > > > > +					
> > > > > BIT(DRM_MODE_BLEND_PIXEL_NONE));
> > > > >    	return plane;
> > > > >    }

Re: [PATCH 1/2] drm/verisilicon: set blend mode for the primary plane

[Icenowy Zheng]

在 2026-09-10四的 10:31 +0200，Thomas Zimmermann写道：
> Hi
> 
> Am 10.09.26 um 10:00 schrieb Icenowy Zheng:
> > 在 2026-09-10四的 09:58 +0200，Thomas Zimmermann写道：
> > > Hi
> > > 
> > > Am 10.09.26 um 09:09 schrieb Icenowy Zheng:
> > > > 在 2026-09-02三的 01:17 +0800，Icenowy Zheng写道：
> > > > > Blend modes are now required to expose pixel formats w/
> > > > > alpha.
> > > > > 
> > > > > As it's the primary plane and blending is explicitly
> > > > > disabled,
> > > > > just
> > > > > expose PIXEL_NONE blend mode.
> > > > Gently ping for reviews.
> > > What do these alpha formats do?  Are they a hardware feature?  It
> > > looks
> > > like they are programmable, but don't differ from XRGB at all.
> > I think they're for consistency with overlay planes.
> 
> But there are no overlay planes in this driver, are there?
> 
> What I want to get at is that it might be preferable to remove ARGB 
> entirely from the primary plane if it does not to serve a purpose.
> But 
> if the driver can do something useful with these formats, it might be
> worth exposing that instead.

On DC8000 display controllers (support for them is WIP by Joey Lu)
there seem to be no way to control the blend behavior of the primary
plane.

On DC8200 display controllers the primary plane does have a blending
register, although it seems to be blending with pure black.

Maybe it's viable to just remove the ARGB formats now, and re-introduce
them when overlays are being implemented (and only expose them for the
overlay)?

Thanks,
Icenowy

> 
> In pl111, we now remove the ARGB foramts because the hardware does
> not 
> handle them at all. The situation seems less clear in verisilicon.
> 
> Best regards
> Thomas
> 
> 
> > 
> > Thanks,
> > Icenowy
> > 
> > > Best regards
> > > Thomas
> > > 
> > > > Thanks,
> > > > Icenowy
> > > > 
> > > > > Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
> > > > > ---
> > > > >    drivers/gpu/drm/verisilicon/vs_primary_plane.c | 3 +++
> > > > >    1 file changed, 3 insertions(+)
> > > > > 
> > > > > diff --git a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> > > > > b/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> > > > > index 1f2be41ae496c..8d58682d88ef8 100644
> > > > > --- a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> > > > > +++ b/drivers/gpu/drm/verisilicon/vs_primary_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_crtc.h>
> > > > >    #include <drm/drm_fourcc.h>
> > > > >    #include <drm/drm_framebuffer.h>
> > > > > @@ -179,5 +180,7 @@ struct drm_plane
> > > > > *vs_primary_plane_init(struct
> > > > > drm_device *drm_dev, struct vs_dc
> > > > >    
> > > > >    	drm_plane_helper_add(plane,
> > > > > &vs_primary_plane_helper_funcs);
> > > > >    
> > > > > +	drm_plane_create_blend_mode_property(plane,
> > > > > +					
> > > > > BIT(DRM_MODE_BLEND_PIXEL_NONE));
> > > > >    	return plane;
> > > > >    }

Re: [PATCH 1/2] drm/verisilicon: set blend mode for the primary plane

[Thomas Zimmermann]

Hi

Am 10.09.26 um 10:45 schrieb Icenowy Zheng:
> 在 2026-09-10四的 10:31 +0200，Thomas Zimmermann写道：
>> Hi
>>
>> Am 10.09.26 um 10:00 schrieb Icenowy Zheng:
>>> 在 2026-09-10四的 09:58 +0200，Thomas Zimmermann写道：
>>>> Hi
>>>>
>>>> Am 10.09.26 um 09:09 schrieb Icenowy Zheng:
>>>>> 在 2026-09-02三的 01:17 +0800，Icenowy Zheng写道：
>>>>>> Blend modes are now required to expose pixel formats w/
>>>>>> alpha.
>>>>>>
>>>>>> As it's the primary plane and blending is explicitly
>>>>>> disabled,
>>>>>> just
>>>>>> expose PIXEL_NONE blend mode.
>>>>> Gently ping for reviews.
>>>> What do these alpha formats do?  Are they a hardware feature?  It
>>>> looks
>>>> like they are programmable, but don't differ from XRGB at all.
>>> I think they're for consistency with overlay planes.
>> But there are no overlay planes in this driver, are there?
>>
>> What I want to get at is that it might be preferable to remove ARGB
>> entirely from the primary plane if it does not to serve a purpose.
>> But
>> if the driver can do something useful with these formats, it might be
>> worth exposing that instead.
> On DC8000 display controllers (support for them is WIP by Joey Lu)
> there seem to be no way to control the blend behavior of the primary
> plane.
>
> On DC8200 display controllers the primary plane does have a blending
> register, although it seems to be blending with pure black.

IIRC there's a background-color property for the CRTC.  So it might be 
possible to expose this as read-only property. (Not sure.)

>
> Maybe it's viable to just remove the ARGB formats now, and re-introduce
> them when overlays are being implemented (and only expose them for the
> overlay)?

I see. Thanks for digging through this. I've meanwhile acked the patches 
as there's at least some support in hardware.

Best regards
Thomas


>
> Thanks,
> Icenowy
>
>> In pl111, we now remove the ARGB foramts because the hardware does
>> not
>> handle them at all. The situation seems less clear in verisilicon.
>>
>> Best regards
>> Thomas
>>
>>
>>> Thanks,
>>> Icenowy
>>>
>>>> Best regards
>>>> Thomas
>>>>
>>>>> Thanks,
>>>>> Icenowy
>>>>>
>>>>>> Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
>>>>>> ---
>>>>>>     drivers/gpu/drm/verisilicon/vs_primary_plane.c | 3 +++
>>>>>>     1 file changed, 3 insertions(+)
>>>>>>
>>>>>> diff --git a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
>>>>>> b/drivers/gpu/drm/verisilicon/vs_primary_plane.c
>>>>>> index 1f2be41ae496c..8d58682d88ef8 100644
>>>>>> --- a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
>>>>>> +++ b/drivers/gpu/drm/verisilicon/vs_primary_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_crtc.h>
>>>>>>     #include <drm/drm_fourcc.h>
>>>>>>     #include <drm/drm_framebuffer.h>
>>>>>> @@ -179,5 +180,7 @@ struct drm_plane
>>>>>> *vs_primary_plane_init(struct
>>>>>> drm_device *drm_dev, struct vs_dc
>>>>>>     
>>>>>>     	drm_plane_helper_add(plane,
>>>>>> &vs_primary_plane_helper_funcs);
>>>>>>     
>>>>>> +	drm_plane_create_blend_mode_property(plane,
>>>>>> +					
>>>>>> BIT(DRM_MODE_BLEND_PIXEL_NONE));
>>>>>>     	return plane;
>>>>>>     }

-- 
--
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)

Re: [PATCH 1/2] drm/verisilicon: set blend mode for the primary plane

[Icenowy Zheng]

在 2026-09-10四的 10:56 +0200，Thomas Zimmermann写道：
> Hi
> 
> Am 10.09.26 um 10:45 schrieb Icenowy Zheng:
> > 在 2026-09-10四的 10:31 +0200，Thomas Zimmermann写道：
> > > Hi
> > > 
> > > Am 10.09.26 um 10:00 schrieb Icenowy Zheng:
> > > > 在 2026-09-10四的 09:58 +0200，Thomas Zimmermann写道：
> > > > > Hi
> > > > > 
> > > > > Am 10.09.26 um 09:09 schrieb Icenowy Zheng:
> > > > > > 在 2026-09-02三的 01:17 +0800，Icenowy Zheng写道：
> > > > > > > Blend modes are now required to expose pixel formats w/
> > > > > > > alpha.
> > > > > > > 
> > > > > > > As it's the primary plane and blending is explicitly
> > > > > > > disabled,
> > > > > > > just
> > > > > > > expose PIXEL_NONE blend mode.
> > > > > > Gently ping for reviews.
> > > > > What do these alpha formats do?  Are they a hardware
> > > > > feature?  It
> > > > > looks
> > > > > like they are programmable, but don't differ from XRGB at
> > > > > all.
> > > > I think they're for consistency with overlay planes.
> > > But there are no overlay planes in this driver, are there?
> > > 
> > > What I want to get at is that it might be preferable to remove
> > > ARGB
> > > entirely from the primary plane if it does not to serve a
> > > purpose.
> > > But
> > > if the driver can do something useful with these formats, it
> > > might be
> > > worth exposing that instead.
> > On DC8000 display controllers (support for them is WIP by Joey Lu)
> > there seem to be no way to control the blend behavior of the
> > primary
> > plane.
> > 
> > On DC8200 display controllers the primary plane does have a
> > blending
> > register, although it seems to be blending with pure black.
> 
> IIRC there's a background-color property for the CRTC.  So it might
> be 
> possible to expose this as read-only property. (Not sure.)

The hardware has a "background color" per plane, but it seems that this
is only for the colorkey (punching out special color values) feature,
not for alpha blending.

> 
> > 
> > Maybe it's viable to just remove the ARGB formats now, and re-
> > introduce
> > them when overlays are being implemented (and only expose them for
> > the
> > overlay)?
> 
> I see. Thanks for digging through this. I've meanwhile acked the
> patches 
> as there's at least some support in hardware.

As the DC8000 support is being developed (a new revision of that
patchset just appeared on this Tuesday), and on that hardware the A
channel has no meaning except for being ignored (no blend configuration
register for the primary plane), maybe I still need to remove alpha
formats (at least for DC8000)?

Although in such case, when the overlay support is going to be
introduced, two format tables need to be present -- one with alpha and
one without.

Thanks,
Icenowy

> 
> Best regards
> Thomas
> 
> 
> > 
> > Thanks,
> > Icenowy
> > 
> > > In pl111, we now remove the ARGB foramts because the hardware
> > > does
> > > not
> > > handle them at all. The situation seems less clear in
> > > verisilicon.
> > > 
> > > Best regards
> > > Thomas
> > > 
> > > 
> > > > Thanks,
> > > > Icenowy
> > > > 
> > > > > Best regards
> > > > > Thomas
> > > > > 
> > > > > > Thanks,
> > > > > > Icenowy
> > > > > > 
> > > > > > > Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
> > > > > > > ---
> > > > > > >     drivers/gpu/drm/verisilicon/vs_primary_plane.c | 3
> > > > > > > +++
> > > > > > >     1 file changed, 3 insertions(+)
> > > > > > > 
> > > > > > > diff --git
> > > > > > > a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> > > > > > > b/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> > > > > > > index 1f2be41ae496c..8d58682d88ef8 100644
> > > > > > > --- a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> > > > > > > +++ b/drivers/gpu/drm/verisilicon/vs_primary_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_crtc.h>
> > > > > > >     #include <drm/drm_fourcc.h>
> > > > > > >     #include <drm/drm_framebuffer.h>
> > > > > > > @@ -179,5 +180,7 @@ struct drm_plane
> > > > > > > *vs_primary_plane_init(struct
> > > > > > > drm_device *drm_dev, struct vs_dc
> > > > > > >     
> > > > > > >     	drm_plane_helper_add(plane,
> > > > > > > &vs_primary_plane_helper_funcs);
> > > > > > >     
> > > > > > > +	drm_plane_create_blend_mode_property(plane,
> > > > > > > +					
> > > > > > > BIT(DRM_MODE_BLEND_PIXEL_NONE));
> > > > > > >     	return plane;
> > > > > > >     }

Re: [PATCH 1/2] drm/verisilicon: set blend mode for the primary plane

[Thomas Zimmermann]

Hi

Am 10.09.26 um 11:02 schrieb Icenowy Zheng:
[...]
> As the DC8000 support is being developed (a new revision of that
> patchset just appeared on this Tuesday), and on that hardware the A
> channel has no meaning except for being ignored (no blend configuration
> register for the primary plane), maybe I still need to remove alpha
> formats (at least for DC8000)?
>
> Although in such case, when the overlay support is going to be
> introduced, two format tables need to be present -- one with alpha and
> one without.

Sure. In my opinion, there should be a dedicated format table for each 
type of plane. These "super tables" that sometimes try to catch all 
cases in a single place are not great.

Best regards
Thomas

>
> Thanks,
> Icenowy
>
>> Best regards
>> Thomas
>>
>>
>>> Thanks,
>>> Icenowy
>>>
>>>> In pl111, we now remove the ARGB foramts because the hardware
>>>> does
>>>> not
>>>> handle them at all. The situation seems less clear in
>>>> verisilicon.
>>>>
>>>> Best regards
>>>> Thomas
>>>>
>>>>
>>>>> Thanks,
>>>>> Icenowy
>>>>>
>>>>>> Best regards
>>>>>> Thomas
>>>>>>
>>>>>>> Thanks,
>>>>>>> Icenowy
>>>>>>>
>>>>>>>> Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
>>>>>>>> ---
>>>>>>>>      drivers/gpu/drm/verisilicon/vs_primary_plane.c | 3
>>>>>>>> +++
>>>>>>>>      1 file changed, 3 insertions(+)
>>>>>>>>
>>>>>>>> diff --git
>>>>>>>> a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
>>>>>>>> b/drivers/gpu/drm/verisilicon/vs_primary_plane.c
>>>>>>>> index 1f2be41ae496c..8d58682d88ef8 100644
>>>>>>>> --- a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
>>>>>>>> +++ b/drivers/gpu/drm/verisilicon/vs_primary_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_crtc.h>
>>>>>>>>      #include <drm/drm_fourcc.h>
>>>>>>>>      #include <drm/drm_framebuffer.h>
>>>>>>>> @@ -179,5 +180,7 @@ struct drm_plane
>>>>>>>> *vs_primary_plane_init(struct
>>>>>>>> drm_device *drm_dev, struct vs_dc
>>>>>>>>      
>>>>>>>>      	drm_plane_helper_add(plane,
>>>>>>>> &vs_primary_plane_helper_funcs);
>>>>>>>>      
>>>>>>>> +	drm_plane_create_blend_mode_property(plane,
>>>>>>>> +					
>>>>>>>> BIT(DRM_MODE_BLEND_PIXEL_NONE));
>>>>>>>>      	return plane;
>>>>>>>>      }

-- 
--
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)

Re: [PATCH 1/2] drm/verisilicon: set blend mode for the primary plane

[Thomas Zimmermann]

Am 01.09.26 um 19:17 schrieb Icenowy Zheng:
> Blend modes are now required to expose pixel formats w/ alpha.
>
> As it's the primary plane and blending is explicitly disabled, just
> expose PIXEL_NONE blend mode.
>
> Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
> ---
>   drivers/gpu/drm/verisilicon/vs_primary_plane.c | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/verisilicon/vs_primary_plane.c b/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> index 1f2be41ae496c..8d58682d88ef8 100644
> --- a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> +++ b/drivers/gpu/drm/verisilicon/vs_primary_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_crtc.h>
>   #include <drm/drm_fourcc.h>
>   #include <drm/drm_framebuffer.h>
> @@ -179,5 +180,7 @@ struct drm_plane *vs_primary_plane_init(struct drm_device *drm_dev, struct vs_dc
>   
>   	drm_plane_helper_add(plane, &vs_primary_plane_helper_funcs);
>   
> +	drm_plane_create_blend_mode_property(plane,
> +					     BIT(DRM_MODE_BLEND_PIXEL_NONE));

No empty line before that call. I think it also fits onto a single line. 
Apart from the style

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>


>   	return plane;
>   }

-- 
--
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)

Re: [PATCH 1/2] drm/verisilicon: set blend mode for the primary plane

[Icenowy Zheng]

在 2026-09-10四的 10:49 +0200，Thomas Zimmermann写道：
> 
> 
> Am 01.09.26 um 19:17 schrieb Icenowy Zheng:
> > Blend modes are now required to expose pixel formats w/ alpha.
> > 
> > As it's the primary plane and blending is explicitly disabled, just
> > expose PIXEL_NONE blend mode.
> > 
> > Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
> > ---
> >   drivers/gpu/drm/verisilicon/vs_primary_plane.c | 3 +++
> >   1 file changed, 3 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> > b/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> > index 1f2be41ae496c..8d58682d88ef8 100644
> > --- a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
> > +++ b/drivers/gpu/drm/verisilicon/vs_primary_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_crtc.h>
> >   #include <drm/drm_fourcc.h>
> >   #include <drm/drm_framebuffer.h>
> > @@ -179,5 +180,7 @@ struct drm_plane *vs_primary_plane_init(struct
> > drm_device *drm_dev, struct vs_dc
> >   
> >   	drm_plane_helper_add(plane,
> > &vs_primary_plane_helper_funcs);
> >   
> > +	drm_plane_create_blend_mode_property(plane,
> > +					    
> > BIT(DRM_MODE_BLEND_PIXEL_NONE));
> 
> No empty line before that call. I think it also fits onto a single

The plane blend mode call exceeds 80 columns (82 columns for COVERAGE
and 83 columns for PIXEL_NONE), although I heard that sometimes the
limit is 100 columns instead (but coding-style.rst still says 80
columns is preferred).

Thanks,
Icenowy

> line. 
> Apart from the style
> 
> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
> 
> 
> >   	return plane;
> >   }

Re: [PATCH 1/2] drm/verisilicon: set blend mode for the primary plane

[Thomas Zimmermann]

Hi

Am 10.09.26 um 11:08 schrieb Icenowy Zheng:
> 在 2026-09-10四的 10:49 +0200，Thomas Zimmermann写道：
>>
>> Am 01.09.26 um 19:17 schrieb Icenowy Zheng:
>>> Blend modes are now required to expose pixel formats w/ alpha.
>>>
>>> As it's the primary plane and blending is explicitly disabled, just
>>> expose PIXEL_NONE blend mode.
>>>
>>> Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
>>> ---
>>>    drivers/gpu/drm/verisilicon/vs_primary_plane.c | 3 +++
>>>    1 file changed, 3 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
>>> b/drivers/gpu/drm/verisilicon/vs_primary_plane.c
>>> index 1f2be41ae496c..8d58682d88ef8 100644
>>> --- a/drivers/gpu/drm/verisilicon/vs_primary_plane.c
>>> +++ b/drivers/gpu/drm/verisilicon/vs_primary_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_crtc.h>
>>>    #include <drm/drm_fourcc.h>
>>>    #include <drm/drm_framebuffer.h>
>>> @@ -179,5 +180,7 @@ struct drm_plane *vs_primary_plane_init(struct
>>> drm_device *drm_dev, struct vs_dc
>>>    
>>>    	drm_plane_helper_add(plane,
>>> &vs_primary_plane_helper_funcs);
>>>    
>>> +	drm_plane_create_blend_mode_property(plane,
>>> +					
>>> BIT(DRM_MODE_BLEND_PIXEL_NONE));
>> No empty line before that call. I think it also fits onto a single
> The plane blend mode call exceeds 80 columns (82 columns for COVERAGE
> and 83 columns for PIXEL_NONE), although I heard that sometimes the
> limit is 100 columns instead (but coding-style.rst still says 80
> columns is preferred).

It's 100 characters now.

Best regards
Thomas


>
> Thanks,
> Icenowy
>
>> line.
>> Apart from the style
>>
>> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
>>
>>
>>>    	return plane;
>>>    }

-- 
--
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)