[PATCH] support for 30 bit depth in dummy driver

[Adam Jackson]

On Sat, 2017-08-05 at 18:10 +0700, Antoine Martin wrote:
> Ping. Please apply.
> 
> This patch has been used for almost a year now, and got tested more
> thoroughly lately with a patch to VirtualGL. To test it with xpra
> 2.1:
> xpra start --pixel-depth 30 --start=xterm --attach=yes

Mostly merged, except for this bit:

> @@ -321,8 +322,8 @@ DUMMYPreInit(ScrnInfoPtr pScrn, int flags)
>         pScrn->rgbBits = 8;
> 
>      /* Get the depth24 pixmap format */
> -    if (pScrn->depth == 24 && pix24bpp == 0)
> -       pix24bpp = xf86GetBppFromDepth(pScrn, 24);
> +    if (pScrn->depth >= 24 && pix24bpp == 0)
> +       pix24bpp = xf86GetBppFromDepth(pScrn, pScrn->depth);

pix24bpp is never read from other than this statement so it doesn't
really matter, but the intent of this bit of boilerplate in other
drivers is to make a decision _only_ about whether the depth-24 pixmap
format is 24bpp or 32bpp, in principle because the former saves VRAM.
For depth 30 screens there's no possible reason to want 24/24 pixmaps,
since you're already paying the price for 32bpp anyway.

- ajax