From: Andi Kleen <ak@suse.de>
To: Jens Axboe <axboe@suse.de>
Subject: Re: PCI-DMA: Out of IOMMU space on x86-64 (Athlon64x2), with solution
Date: Thu, 2 Mar 2006 13:16:37 +0100
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Cc: Michael Monnerie <m.monnerie@zmi.at>,
 Jeff Garzik <jgarzik@pobox.com>
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On Thursday 02 March 2006 10:59, Jens Axboe wrote:

[dropping closed suse list. Please never put both closed and open lists
into the same cc list]

> libata should also handle this case better. Usually we just need to
> defer command handling if the dma_map_sg() fails. Changing
> ata_qc_issue() to return nsegments for success, 0 for defer failure, and
> -1 for permanent failure should be enough. The SCSI path is easy at
> least, as we can just ask for a defer there. The internal qc_issue is a
> little more tricky.

Yes I've been thinking about adding a new sleeping interface to the IOMMU
that would block for new space to handle this. If I did that - would libata be 
able to use it?

-Andi