[RFC] Deprecation and removal of the drm2 driver

[Niclas Zeising]

On 05/18/18 19:58, Niclas Zeising wrote:
> [ Cross posted to freebsd-current@ and freebsd-x11 at .  Please respect 
> reply-to and send all replies to freebsd-x11 at .  Thanks! ]
> 
> 
> Hi!
> I propose that we remove the old drm2 driver (sys/dev/drm2) from 
> FreeBSD.  I suggest the driver is marked as deprecated in 11.x and 
> removed from 12.0, as was done for other drivers recently.  Some 
> background and rationale:
> 
> The drm2 driver was the original port of a KMS driver to FreeBSD.  It 
> was done by Konstantin Belousov to support Intel graphics cards, and 
> later extended by Jean-Sébastien Pédron as well as Konstantin to match 
> what's in Linux 3.8.  This included unstable support from Haswell, but 
> nothing newer than that.
> 
> For quite some time now we have had the graphics/drm-stable-kmod and 
> graphics/drm-next-kmods which provides support for modern AMD and Intel 
> graphics cards.  These ports, together with the linuxkpi, or lkpi, has 
> made it significantly easier to port and update our graphics drivers. 
> Further, these new drivers cover the same drivers as the old drm2 driver.
> 
> What does the community think?  Is there anyone still using the drm2 
> driver on 12-CURRENT?  If so, what is preventing you from switching to 
> the port?
> 


Wow, this blew up quite a lot bigger than I anticipated.  I'll try to 
summarize the discussion a bit below and then suggest a way forward.

The primary reasons we want to do this is because there are conflicts 
between the new drm drivers in ports, and the drm drivers in base, since 
they control the same hardware.  It is hard to make conflicting drivers 
to auto load in a consistent way.  In order to improve the desktop 
experience I'd like to see that graphics drivers are loaded on system 
boot.  There is also a push from upstream to have the xf86-video* 
drivers stop loading driver kernel modules.  It is also easier to keep a 
port updated than keeping the base system updated, and updates can 
propagate to multiple FreeBSD versions at once.  This will also ensure 
that all ports use the same firmware blobs.

So, to the summary.  A lot of people are using i386, and as such still 
need the old drm drivers.  There were also some reports about issues 
with the drm-next/stable drivers, which needs investigating. Power is 
another architecture that also is not supported by drm-next/stable, 
although we hope to extend support to powerpc in the future. There was a 
lot of discussion regarding making it into a port, or only excluding the 
driver on amd64, and similar suggestions.

To move forward, we'll do the following:  Note that this is for current 
only.
We take the drm and drm2 drivers and make a port for it, maintained by 
the graphics team (x11@).  After a transition period, then the drivers 
are removed from base.  At the same time, pkg-messages are added to 
relevant places to point people to the various available drm drivers.

Regards
-- 
Niclas Zeising
FreeBSD graphics/x11 team