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Date: Mon, 28 Sep 2015 14:36:27 +0200
From: Daniel Vetter <daniel@ffwll.ch>
To: Gerd Hoffmann <kraxel@redhat.com>
Cc: David Herrmann <dh.herrmann@gmail.com>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Thomas Petazzoni <thomas.petazzoni@free-electrons.com>,
        linux-fbdev <linux-fbdev@vger.kernel.org>,
        Teddy Wang <teddy.wang@siliconmotion.com>,
        Daniel Vetter <daniel.vetter@ffwll.ch>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        DRI Development <dri-devel@lists.freedesktop.org>,
        Arnaud Patard <apatard@mandriva.com>,
        Tomi Valkeinen <tomi.valkeinen@ti.com>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Dave Airlie <airlied@redhat.com>,
        Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Subject: Re: No more new fbdev drivers, please
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On Mon, Sep 28, 2015 at 09:39:13AM +0200, Gerd Hoffmann wrote:
>   Hi,
> 
> > As Daniel mentioned, the connector+encoder+crtc combination is one of
> > those simplifications that would make sense if more such drivers are
> > added.
> 
> Another one is memory management.  It's pretty complex because it can
> handle _way_ more than what simple drivers need, and the result is
> _alot_ of ttm boilerplate in the drivers.

ttm is pretty impressive overkill for most simplistic drm drivers. If you
just need contiguous framebuffers for display then the cma helpers should
take care of pretty much all the boilerplate for you. They have ready-made
simple gem and dumb framebuffer mmap support, which is all a basic kms
driver needs.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch