From: Jeff Garzik <jeff@garzik.org>
To: Tejun Heo <htejun@gmail.com>
Cc: Mark Lord <liml@rtr.ca>,
IDE/ATA development list <linux-ide@vger.kernel.org>
Subject: Re: WARNING: at drivers/ata/libata-core.c:5988 ata_qc_issue()
Date: Fri, 25 Jan 2008 02:20:20 -0500 [thread overview]
Message-ID: <47998DB4.8000207@garzik.org> (raw)
In-Reply-To: <47996738.8030908@gmail.com>
Tejun Heo wrote:
> Mark Lord wrote:
>> Another one for those beers, is a way to tell the IOMMU code about
>> physical segment limitations -- so we can stop having to allocate
>> PRD tables 2X as big as necessary in drivers like sata_mv.
>
> Hmmm... What's the restriction for sata_mv? The same as BMDMA? We need
> to update the block layer too to get the BMDMA right.
Same as for BMDMA, specifically: after block/etc. merging is done, and
things are passed to the IOMMU via dma_map_sg(), the IOMMU may merge
-too- aggressively, merging across boundaries (like 64k bmdma boundary)
because it is unaware of such restrictions.
Jeff
next prev parent reply other threads:[~2008-01-25 7:20 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-24 15:20 WARNING: at drivers/ata/libata-core.c:5988 ata_qc_issue() Mark Lord
2008-01-24 15:26 ` Tejun Heo
2008-01-24 15:56 ` Mark Lord
2008-01-24 23:36 ` Tejun Heo
2008-01-24 23:52 ` Mark Lord
2008-01-24 23:57 ` Tejun Heo
2008-01-25 0:02 ` Mark Lord
2008-01-25 0:07 ` Tejun Heo
2008-01-25 4:01 ` Mark Lord
2008-01-25 4:08 ` Tejun Heo
2008-01-25 4:29 ` Mark Lord
2008-01-25 4:36 ` Tejun Heo
2008-01-25 7:20 ` Jeff Garzik [this message]
2008-01-25 7:18 ` Jeff Garzik
2008-01-25 15:01 ` James Bottomley
2008-01-25 15:18 ` Mark Lord
2008-01-25 15:29 ` James Bottomley
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