Re: 3.0-STABLE / drm-kmod / dual radeon problems

Gary Jennejohn <gljennjohn@gmail.com> wrote:

> On Fri, 20 Aug 2021 06:56:27 -0500
> Scott Bennett <bennett@sdf.org> wrote:
>
> > Alexey Dokuchaev <danfe@freebsd.org> wrote:
> > 
> > > On Thu, Aug 19, 2021 at 11:51:36AM -0700, John Kennedy wrote:  
> > > > [resending to freebsd-x11@ vs x11@]
> > > > 
> > > > I'm making my semi-annual attempt to convert a windows box to a FreeBSD
> > > > box and having the same kind of issues.  It is a Dell Optiplex 9020 with
> > > > dual radeon cards (and currently 3 monitors, 4 if I can get it to work).  
> > >
> > > Similar question (about dual Radeon cards) had been asked on this list
> > > before* and never answered, AFAIK.  Apparently, this configuration does
> > > not look interesting for developers to test and provide support for. :(
> > >
> > > ./danfe
> > >
> > > *) https://lists.freebsd.org/pipermail/freebsd-x11/2020-September/026609.html
> > >  
> >      I will add that they also seem unwilling to answer whether a firmware bug
> > that hangs a single Radeon card has even been reported upstream, whether to
> > X.org or to AMD.  They are also unwilling to say whether the DRM bug that
> > attempts to perform a hard reboot (i.e., without so much as sync(), let alone an
> > orderly shutdown with UFS unmounts, etc.) in response to a hung GPU has been
> > reported upstream.
> >      It ought to be a FreeBSD Foundation project to drum up money to hire a
> > professional GPU programmer (perhaps part-time) and a full-time programmer for
> > CPU-side graphics support.  The latter could devote some of his time toward
> > managing the graphics team's projects and objectives.  With these, perhaps
> > FreeBSD could finally have native graphics support instead of having to import
> > ever more of the LINUX kernel into FreeBSD in order to have graphics, even buggy
> > graphics, at all.
> > 
>
> Why should the manufacturers of graphics hardware jump on a FreeBSD
> bandwagon when they already have lots of Linux developers either
> employed or with NDAs available to do the dirty work?
>
     Oh, I agree completely.  That is why I proposed a different solution, which
would be an application of one of the reasons the Foundation was created.

> I must say that the project is lucky that Nvidia is still willing to
> provide drivers to FreeBSD.

     I suppose it is.  However, we were discussing AMD, which turned over a new leaf
many years ago and now releases its GPU documentation to OS development teams.  It
also provides firmware for its GPUs, but has rather debatable maintenance policies
for it.
>
> Based on my experience from the time when I was developing drivers for
> ISDN cards for FreeBSD, hardware vendors simply don't have FreeBSD on
> their radars.  Even though I signed a NDA with AVM (one of the bigger
> ISDN card vendors), I couldn't get any useful information from them at
> all.  I was basically forced to reverse engineer the Linux drivers. 
> Evidently, Linux developers were considered to be a more interesting
> target than any BSD developer.  And that is still the case today.
>
     As far as I am aware, such is not the case with AMD.  The documentation is
available, so native drivers for Radeon cards can be written, but it would be best
done by an experienced specialist, who would *not* be just a volunteer but rather a
paid employee or contractor.
     It might even be possible to get the NetBSD Foundation and the OpenBSD
Foundation to pool some resources with the FreeBSD Foundation to hire the needed
programmers to develop a native driver that could be built for any of the three.
A generalized, portable BSD driver that avoided all the LINUX crud would be a very
welcome addition to each of the BSDs.  (N.B.  DragonflyBSD does not currently have
a foundation for fundraising, outreach, etc.)


                                  Scott Bennett, Comm. ASMELG, CFIAG
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