From: "H. Peter Anvin" <hpa@zytor.com>
To: Dave Airlie <airlied@gmail.com>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>,
Brice Goglin <brice.goglin@gmail.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
David Airlie <airlied@linux.ie>,
dri-devel@lists.freedesktop.org,
Andy Lutomirski <luto@amacapital.net>
Subject: Re: MTRR use in drivers
Date: Sun, 23 Jun 2013 13:38:46 -0700 [thread overview]
Message-ID: <51C75CD6.5010206@zytor.com> (raw)
In-Reply-To: <CAPM=9tzkJTf4d=HfBUs3VwmNG1+Zo5J-JURYd4mYcJ82yXZOKg@mail.gmail.com>
On 06/23/2013 01:30 PM, Dave Airlie wrote:
>>>> Why do you care about performance when PAT is disabled?
>
> breaking old boxes just because, is just going to get reverted when I
> get the first regression report that you broke old boxes.
>
Not "just because", but *if* the choice is between breaking old boxes
and breaking new boxes I'll take the latter.
> Andy Lutomirski just submitted a bunch of patches to clean up the DRM
> usage of mtrrs, they are in drm-next, afaik we no longer add them on
> PAT systems.
Fantastic news. No issue, then, and no need to break anything.
The only problem I see with having ioremap_wc() installing an MTRR on
non-PAT, rather than pushing that into the drivers which is clearly not
the right thing, is that we will need a hook to uninstall it when the
mapping is destroyed.
-hpa
next prev parent reply other threads:[~2013-06-23 20:38 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-21 5:00 MTRR use in drivers H. Peter Anvin
2013-06-23 6:35 ` Brice Goglin
2013-06-23 14:07 ` H. Peter Anvin
2013-06-23 14:07 ` H. Peter Anvin
2013-06-23 19:29 ` Henrique de Moraes Holschuh
2013-06-23 20:02 ` H. Peter Anvin
2013-06-23 20:30 ` Dave Airlie
2013-06-23 20:38 ` H. Peter Anvin [this message]
2013-06-23 20:54 ` Dave Airlie
2013-06-23 20:58 ` H. Peter Anvin
2013-06-23 21:27 ` Dave Airlie
2013-06-23 21:27 ` Dave Airlie
2013-06-23 23:09 ` Andy Lutomirski
2013-06-23 21:56 ` Henrique de Moraes Holschuh
2013-06-23 22:10 ` H. Peter Anvin
2013-06-23 22:10 ` H. Peter Anvin
2013-06-24 0:02 ` Henrique de Moraes Holschuh
2013-06-24 0:31 ` H. Peter Anvin
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