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Message-ID: <1491833847.30990.77.camel@redhat.com>
Subject: Re: [RfC PATCH] drm: fourcc byteorder: brings header file comments
 in line with reality.
From: Gerd Hoffmann <kraxel@redhat.com>
To: Pekka Paalanen <ppaalanen@gmail.com>
Cc: dri-devel@lists.freedesktop.org,
        open list <linux-kernel@vger.kernel.org>,
        amd-gfx@lists.freedesktop.org, Daniel Vetter <daniel.vetter@intel.com>
Date: Mon, 10 Apr 2017 16:17:27 +0200
In-Reply-To: <20170410161214.305f5daf@eldfell>
References: <20170410101202.19229-1-kraxel@redhat.com>
         <20170410161214.305f5daf@eldfell>
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  Hi,

> which software have you used as representative of "reality"?

ppc64 (big endian) virtual machine, running with qemu stdvga & bochs-drm
driver.  Xorg with modesetting driver uses DRM_FORMAT_XRGB8888 (one and
only format supported by bochs-drm), and we have to interpret that in
bigendian byte order on the host side to get a correct display.

Didn't try wayland.  Can do, but will take a while.  Don't have a
wayland-capable guest install at hand, and installing one takes a while
because I don't have a physical pseries and emulation is slooooww.

> To solve that problem, we would like to know if anything existing would
> break for each possible solution, but no developers using BE have really
> turned up.

That is part of the problem.
And even ppc is moving to little endian these days ...

cheers,
  Gerd