Linux Virtualization - Jul 2018 - [PATCH] drm/cirrus: flip default to 32bpp

On Fri, Jul 06, 2018 at 02:35:07PM -0400, Adam Jackson
wrote:
> On Fri, 2018-07-06 at 11:12 +0200, Gerd Hoffmann wrote:
> > cirrus can handle 1024x768 (and slightly higher) with 24bpp depth.
> > cirrus can handle up to 800x600 with 32bpp.
> 
> 16bpp is maybe a better choice? Nobody's using cirrus because they care
> about color fidelity and it'll use less CPU to update. There's
> precedent here, mgag200 defaults to 16bpp on sufficiently memory-
> impaired devices.
Yeah nouveau does the same fallback to 16bpp if there's not enough vram.
So do a bunch of other drivers.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

On Mon, Jul 09, 2018 at 09:39:24AM +0200, Daniel Vetter
wrote:
> On Fri, Jul 06, 2018 at 02:35:07PM -0400, Adam Jackson wrote:
> > On Fri, 2018-07-06 at 11:12 +0200, Gerd Hoffmann wrote:
> > > cirrus can handle 1024x768 (and slightly higher) with 24bpp
depth.
> > > cirrus can handle up to 800x600 with 32bpp.
> > 
> > 16bpp is maybe a better choice? Nobody's using cirrus because they
care
> > about color fidelity and it'll use less CPU to update. There's
> > precedent here, mgag200 defaults to 16bpp on sufficiently memory-
> > impaired devices.
> 
> Yeah nouveau does the same fallback to 16bpp if there's not enough
vram.
> So do a bunch of other drivers.
Makes sense.  But appearently 16bpp support bitrotted over time, when
just flipping the default the driver Oopses at init time.  I'll look
into it.

cheers,
  Gerd