kernel modesetting progress report....

[Jerome Glisse]

On Thu, 28 Feb 2008 16:53:46 +1000
"Dave Airlie" <airlied at gmail.com> wrote:

> So just to let people know where kernel modesetting is getting to and
> what I'm up to with it..
> 
> So I really want to ship something in Fedora 9 with kernel modesetting
> in it, whether this is a default or a special boot option for the user
> I won't decide for a while.
> 
> But with this in mind I've checked in bunch of changes to the
> modesetting drm to make modesetting optional for i915, you now load
> the i915 module with modeset=1 to enable it.
> I've also created an intel-kernelmode branch which is based on the
> intel-batchbuffer branch, with fairly clean modesetting integration.
> It still needs work to fixup a few features but I'm going to work my
> way through the list.
> (it needs fixes for rotation + video at the moment)
> 
> The DDX driver can detect whether modesetting is enabled in the drm
> and does the right thing for each case.
> 
> I checked a patch into the server to allow the crtc callback to work,
> I think this breaks ABI with xf86Crtc.c users, need to confirm what
> the proper action for this is.
> 
> Dave.

Dave there is one things that is needed to be redone: frame buffer
creation & handling. And i would like we not freeze the API until
we had some time to play with it a bit. So i guess my question is
does this means modesetting API get freezed or not ?

For frame buffer create i believe we need some kind of properties
system where userspace can ask for driver specific properties at
creation time. Also we need a way to allow to query the actual
framebuffer properties (ie one asked at creation might not work
and driver can adjust them so userspace have to requery properties
to know what have been done). 

I also would like the BO argument to become optional ie if none
is supplied it's up to the driver to allocate a BO which fit
with the asked properties. Corollary frame buffer creation can
fail if supplied BO ain't big enough for the asked framebuffer
properties.

Finaly i am wondering if we should not provide some way to
update & get part of the framebuffer this could be especialy
usefull in case of dumb userspace which can't understand
framebuffer properties and if we ever have hw which can't have
linear framebuffer but need to store it in some strange
format (maybe embedded device already fall in this category).

Oh and modesetting can refuse to set mode if supplied framebuffer
don't fit conditions.

Cheers,
Jerome Glisse