[Freedreno] MSM DRM on the Kernel 3.10

[Rob Clark]

On Mon, Mar 3, 2014 at 8:19 AM, Ilia Lin <ilia.lin at gmail.com> wrote:
> Hello Rob,
>
> My name is Ilia and I'm trying to make the freedreno working with the
> msm-3.10 kernel.
> Could you suggest me a way to backport the msm drm/kms kernel driver to the
> 3.10 kernel? may be you know about such experiment?

I don't have any device which runs msm-3.10 kernel (I don't think..
well, maybe the dragonboard apq8074?)..

*but* my general approach to keep drm/msm in sync between upstream and
the various different downstream kernels is to backport latest
upstream drm, and any changes outside drm which it depends on
(dmabuf/reservation/etc).  For the drm stuff it is usually a kinda
ugly "brute force" backport (ie. roughly 'cp -r' then revert some
little things here and there).  For the changes outside of drm which I
need to backport, I cherry-pick the individual commits, so it is
easier to see.  (Doing that for the drivers/gpu/drm changes would mean
1000's of patches, which is why I only do this for the relatively
smaller amount of changes I need to backport, outside of drm.)

In theory 3.10 should be easier than 3.4, since it is not quite as far
out of date.  But it might take some trial and error.  You probably
want to keep my 3.4 based branch handy for reference (that way you can
check how I resolved issues for APIs that drm uses from rest of
kernel, like backlight changes, etc).

I'm not sure if msm-3.10 is pure-devicetree based kernel.  The drm/msm
driver is using DT for mdp5/a330 (since that is what is used for
apq8x74 on msm-3.4 kernel).  I have started a while back on DT
bindings for mdp4/a320, to get upstream kernel working.  But still
work in progress.  I'm not sure what device you are using, but if it
is mdp4 then there is some work needed.

BR,
-R

> Thanks in advance,
>
> BR,
> Ilia Lin