From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Dave Airlie <airlied@gmail.com>
Cc: dri-devel <dri-devel@lists.freedesktop.org>
Subject: Re: ongoing writecombine on ppc
Date: Fri, 02 Oct 2015 14:56:13 +1000 [thread overview]
Message-ID: <1443761773.2828.70.camel@kernel.crashing.org> (raw)
In-Reply-To: <CAPM=9txS0Oh+63GkjUURiQ8itNQhCuYgH79qaEsNz37kyRU+Eg@mail.gmail.com>
On Fri, 2015-10-02 at 14:53 +1000, Dave Airlie wrote:
> On 2 October 2015 at 14:45, Benjamin Herrenschmidt
> <benh@kernel.crashing.org> wrote:
> > On Fri, 2015-10-02 at 14:42 +1000, Dave Airlie wrote:
> > > I don't think we resolved this the last time we talked about it,
> > >
> > > but radeon writecombine maps fail hard on ppc, I think all the
> > > fixes
> > > either did something bad to AGP systems or weren't liked.
> > >
> > > My patch attached just fixes radeon, which is where I'm still
> > > seeing
> > > the issue.
> >
> > Yes, you MUST NOT set the flags of system memory to anything other
> > than
> > fully cachable on any cache coherent powerpc machine. This should
> > be
> > bolted into the DRM core imho.
> >
>
> Except you guys screwed up and allowed AGP to exist on Power, and
> that requires it.
Well, Apple did :-) Yes, AGP should never have existed in the first
place, I think that's a given :)
> So we have to keep the AGP trapdoor in place, and at the moment only
> the drivers know if they are AGP, hence why I had to add this in the
> driver instead of in the drm core.
Cheers,
Ben.
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2015-10-02 4:56 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-02 4:42 ongoing writecombine on ppc Dave Airlie
2015-10-02 4:45 ` Benjamin Herrenschmidt
2015-10-02 4:47 ` Benjamin Herrenschmidt
2015-10-02 4:50 ` Benjamin Herrenschmidt
2015-10-02 4:53 ` Dave Airlie
2015-10-02 4:56 ` Benjamin Herrenschmidt [this message]
2016-01-21 15:24 ` Oded Gabbay
2016-01-21 15:39 ` Oded Gabbay
2016-01-21 17:10 ` Alex Deucher
2016-01-22 2:32 ` Michel Dänzer
2016-01-28 14:30 ` Oded Gabbay
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1443761773.2828.70.camel@kernel.crashing.org \
--to=benh@kernel.crashing.org \
--cc=airlied@gmail.com \
--cc=dri-devel@lists.freedesktop.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox