deprecation of drm-legacy-kmod

[Chris]

On 2020-08-27 17:07, Warner Losh wrote:
> On Thu, Aug 27, 2020 at 11:28 AM Chris <bsd-lists at bsdforge.com> wrote:
> 
>> On 2020-08-24 15:21, Niclas Zeising wrote:
>> > [ cross posted across several mailing lists, please respect reply-to ]
>> >
>> > Hi!
>> >
>> > It is time to deprecate drm-legacy-kmod, since it is taking too much
>> time to
>> > maintain and are holding off changes in other areas.
>> >
>> > drm-legacy-kmod was created to aid in the transition to the LinuxKPI
>> based
>> > graphics drivers, at a time when the new drivers only supported amd64.
>> > Since
>> > then, the new drivers have been updated to support more architectures
>> and
>> > more
>> > GPUs, and the burden of maintaining drm-legacy-kmod has increased.  It
>> > became
>> > apparent with the update of xorg-server to 1.20 that drm-legacy-kmod is
>> too
>> > old to
>> > work with certain aspects of the graphics stack, and it is also holding
>> back
>> > changes in areas of the FreeBSD base system such as VM scaling and
>> > optimization.
>> > The VM locking protocol needs to be changed, and to port those changes
>> to
>> > these
>> > drivers would require extensive reworking of its use of the FreeBSD VM
>> > subsystem.
>> > This means it is time for it to go.
>> >
>> > The driver will remain for a transition period.  For FreeBSD 13-CURRENT,
>> > this will
>> > be fairly short, as there are changes to FreeBSD base that breaks the
>> > drivers.
>> > For FreeBSD 12, the driver will remain a bit longer, to ease in
>> transition.
>> > On
>> > FreeBSD 12, there is also the option of using the graphics drivers in
>> base,
>> > although those are supported on a best-effort basis only.
>> If this were pulled today. What are the ramifications? IOW what (A)GPUs
>> would
>> no longer be available for use on FreeBSD? Does one need to join a Linux
>> Graphics
>> list to find out what's currently supported? If so. What version of the
>> Linux
>> kernel?
>> 
> 
> The ramifications are three fold.
> 
> (1) There's some truly ancient graphics hardware that won't be supported
> anymore. However they still work on stable 11 and stable 12.
> (2) Improvements to the scaling of VM system can proceed forward.
> (3) Efforts can be focused on the 5.4 Linux port that's in progress and
> testing in -current.
I was actually more concerned for what hardware would no longer be supported.
That is; what (specific) hardware was now off the table as a result of this
change. Not really a concern for my own hardware -- I stay relatively 
current.
But rather for current, and future customers.
I guess I just assumed that the "legacy" branch was specific to specific
video cards, and processors, and that someone knew what they were.

Thank you for taking the time to reply, Warner.

--Chris
> 
> For most people, though, this doesn't matter. It's not used by default and
> you have to specifically opt into using it.
> 
> Warner