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@xxxxxxxxxxx>
> > > > ---
> > > >    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)