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From: Scott Wood <scottwood@freescale.com>
To: Mike Winter <mike.winter@vecimanetworks.com>
Cc: linuxppc-embedded@ozlabs.org
Subject: Re: PCI DMA Problems With 82xx?
Date: Tue, 17 Jun 2008 16:29:42 -0500	[thread overview]
Message-ID: <48582CC6.60004@freescale.com> (raw)
In-Reply-To: <4858113F.4050203@vecimanetworks.com>

Mike Winter wrote:
> We are developing with an 8248-based platform, and we have a vendor 
> telling us that the PCI hardware is unreliable on this CPU family, in 
> particular the DMA functionality.  A quick search of this list doesn't 
> turn up any horror stories, although the processor does have some PCI 
> errata listed.  Does anybody have any practical experience using PCI on 
> the 8248 or similar that they can share with me?   Thanks.

Make sure that you park the bus on PCI, and elevate PCI's arbitration 
priority.  See fixup_pci() in arch/powerpc/boot/cuboot-pq2.c.

I haven't had a problem with PCI DMA when that is done, though I haven't 
done significant stress testing.

-Scott

  reply	other threads:[~2008-06-17 21:29 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-06-17 19:32 PCI DMA Problems With 82xx? Mike Winter
2008-06-17 21:29 ` Scott Wood [this message]
2008-06-17 21:49   ` Rune Torgersen
2008-06-17 21:51     ` Rune Torgersen
2008-06-17 21:52     ` Scott Wood
2008-06-18 13:32   ` Anybody have an mpc5200b mscan linux driver under 2.6.24, ARCH=powerpc or equiv? Mike Timmons
2008-06-18 13:45     ` Wolfgang Grandegger
2008-06-18 14:02       ` Mike Timmons
2008-06-18 14:18         ` Wolfgang Grandegger
2008-06-18 16:16           ` Mike Timmons
2008-06-19 10:38         ` Daniel Schnell

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