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Date:   Wed, 8 Aug 2018 10:46:05 +0200
From:   Gerd Hoffmann <kraxel@redhat.com>
To:     Adam Jackson <ajax@redhat.com>, dri-devel@lists.freedesktop.org,
        David Airlie <airlied@linux.ie>,
        Dave Airlie <airlied@redhat.com>,
        open list <linux-kernel@vger.kernel.org>,
        "open list:DRM DRIVER FOR QEMU'S CIRRUS DEVICE" 
        <virtualization@lists.linux-foundation.org>
Subject: Re: [PATCH] drm/cirrus: flip default to 32bpp
Message-ID: <20180808084605.bnunbipv3uqxkmst@sirius.home.kraxel.org>
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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