[PATCH] [rfc] drm: add some caps for userspace to discover more info for dumb KMS driver

Alan Cox alan at lxorguk.ukuu.org.uk
Thu Sep 29 11:41:11 PDT 2011

On Thu, 29 Sep 2011 16:26:32 +0100
Dave Airlie <airlied at gmail.com> wrote:

> From: Dave Airlie <airlied at redhat.com>
> For the simple KMS driver case we need some more info about argb cursor
> limits and a preferred depth and if shadowed framebuffer access is preferred.
> I've only added this for intel/radeon which support the dumb ioctls so far.
> I really don't want to expose a truck load of info, just enough for X to
> start without configuration with a hw cursor.

Actually there is probably one other thing to report - which is whether
the buffers are cached. That general piece of info "front/back buffer
cached/uncached" allows you to both make intelligent decisions about
using back buffers and also about which copy algorithms to use.

I guess X could work it out by timing algorithms at start up.

Also you call this max cursor width - in some devices isn't it actually a
fixed cursor width ?

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