[PATCH 1/3] drm/radeon: remove AGP support

[Alex Deucher]

On Tue, May 12, 2020 at 4:16 AM Michel Dänzer <michel at daenzer.net> wrote:
>
> On 2020-05-11 10:12 p.m., Alex Deucher wrote:
> > On Mon, May 11, 2020 at 1:17 PM Christian König
> > <ckoenig.leichtzumerken at gmail.com> wrote:
> >>
> >> AGP is deprecated for 10+ years now and not used any more on modern hardware.
> >>
> >> Old hardware should continue to work in PCI mode.
> >
> > Might want to clarify that there is no loss of functionality here.
> > Something like:
> >
> > "There is no loss of functionality here.  GPUs will continue to
> > function.  This just drops the use of the AGP MMU in the chipset in
> > favor of the MMU on the device which has proven to be much more
> > reliable.  Due to its unreliability, AGP support has been disabled on
> > PowerPC for years already so there is no change on PowerPC."
>
> There's a difference between something being disabled by default or not
> being available at all. We may decide it's worth it anyway, but let's do
> it based on facts.
>

I didn't mean to imply that AGP GART support was already removed.  But
for the vast majority of users the end result is the same.  If you
knew enough re-enable AGP GART, you probably wouldn't have been as
confused about what this patch set does either.  To reiterate, this
patch set does not remove support for AGP cards, it only removes the
support for AGP GART.  The cards will still be functional using the
device GART.  There may be performance tradeoffs there in some cases.

Alex