Re: MediaGX/GeodeGX1 requires X86_OOSTORE.

From: takada
Date: Sat Feb 17 2007 - 09:12:25 EST


From: lsorense@xxxxxxxxxxxxxxxxxxx (Lennart Sorensen)
Subject: Re: MediaGX/GeodeGX1 requires X86_OOSTORE. (Was: Re: Strange connection slowdown on pcnet32)
Date: Fri, 16 Feb 2007 19:00:19 -0500

> On Fri, Feb 16, 2007 at 05:48:24PM -0500, Lennart Sorensen wrote:
> > Well so far it really looks like enabling OOSTORE on the Geode
> > SC1200/GX1 really does make a difference. A bit of searching seems to
> > indicate the person that originally submitted the patch that enabled
> > load/store reordering on the MediaGX/Geode though it might need OOSTORE,
> > but was convinced by others it didn't. Looks like it really does need
> > it. The failure that occoured before within a few seconds of starting a
> > large transfer, no longer fails and all I did was enable
> > CONFIG_X86_OOSTORE, and recompile pcnet32.ko and load the new module on
> > the running system. Moving back to the pcnet32.ko built without OOSTORE
> > enabled hits the failure again within seconds, until ifconfig eth1
> > down/up reinitialized it's descriptor ring, after which it survices
> > another bit of transfer and then fails again.
>
> Well forcing load/store serialize on the CPU doesn't help, disalbing
> memory bypass doesn't help. Enabling the X86_OOSTORE does help. What a
> stupid CPU design.

is it mean what doesn't help with doesn't call set_cx86_reoder()?
this function disable to reorder at 0x4000:0000 to 0xffff:ffff.
does pcnet32 access at out of above range?

--- arch/i386/Kconfig.cpu~ 2007-02-05 03:44:54.000000000 +0900
+++ arch/i386/Kconfig.cpu 2007-02-17 21:25:52.000000000 +0900
@@ -322,7 +322,7 @@ config X86_USE_3DNOW

config X86_OOSTORE
bool
- depends on (MWINCHIP3D || MWINCHIP2 || MWINCHIPC6) && MTRR
+ depends on (MWINCHIP3D || MWINCHIP2 || MWINCHIPC6) && MTRR || MGEODEGX1
default y

config X86_TSC
-
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