From: Jarod Wilson <jarod@redhat.com>
Organization: Red Hat, Inc.
To: linux1394-devel@lists.sourceforge.net
Subject: Re: [PATCH] firewire: fw-ohci: fix possible IOMMU resource exhaustion
Date: Wed, 10 Dec 2008 15:16:03 -0500
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Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>, linux-kernel@vger.kernel.org
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On Tuesday 09 December 2008 18:20:38 Stefan Richter wrote:
> There is a DMA map/ unmap imbalance whenever a block write request
> packet is sent and then dequeued with ohci_cancel_packet.  The latter
> may happen frequently if the AR resp tasklet is executed before the AT
> req tasklet for the same transaction.
> 
> Add the missing dma_unmap_single.
> 
> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

Going to get this into the Fedora kernels ASAP, definitely looks like
it'll at least help w/the IOMMU issues.

Nb: from what I recall, I saw such problems on an 8-way opteron pretty
frequently with a debug-enabled kernel, haven't seen it on the same
box running a release kernel (but also haven't tried the bug reporters
reproducer).

Signed-off-by: Jarod Wilson <jarod@redhat.com>

-- 
Jarod Wilson
jarod@redhat.com
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