Re: [PATCH v5 4/4] drm/rockchip: vop2: Support setting custom background color

Andy Shevchenko
2026-01-27T14:45:49Z

On Tue, Jan 27, 2026 at 10:45:36AM +0200, Cristian Ciocaltea wrote:
> The Rockchip VOP2 display controller allows configuring the background
> color of each video output port.
>
> Since a previous patch introduced the BACKGROUND_COLOR CRTC property,
> which defaults to solid black, make use of it when programming the
> hardware.
>
> Note the maximum precision allowed by the display controller is 10bpc,
> while the alpha component is not supported, hence ignored.

...

> + /*
> + * Background color is programmed with 10 bits of precision.
> + * Since performance is more important than accuracy here,
> + * do *not* make use of the DRM_ARGB64_GET*_BPC() helpers.
> + */
> + val = FIELD_PREP(RK3568_VP_DSP_BG__DSP_BG_RED, DRM_ARGB64_GETR(bgcolor) >> 6);
> + val |= FIELD_PREP(RK3568_VP_DSP_BG__DSP_BG_GREEN, DRM_ARGB64_GETG(bgcolor) >> 6);
> + val |= FIELD_PREP(RK3568_VP_DSP_BG__DSP_BG_BLUE, DRM_ARGB64_GETB(bgcolor) >> 6);

There is FIELD_MODIFY() for a few cycles already.
But here it probably makes no much difference.

...

> + seq_printf(s, "\tbackground color (10bpc): r=0x%x g=0x%x b=0x%x\n",
> + DRM_ARGB64_GETR(cstate->background_color) >> 6,
> + DRM_ARGB64_GETG(cstate->background_color) >> 6,
> + DRM_ARGB64_GETB(cstate->background_color) >> 6);

Probably you want to have the alternative to the DRM_ARGB64_GETx() macros which
incorporates a right-shift. But it all in regard to DRM style and preferences.

--
With Best Regards,
Andy Shevchenko