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From: Joerg Roedel <joro@8bytes.org>
To: James Georgas <james.georgas@yahoo.ca>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Integrated MegaRAID controller and AMD IOMMU issue
Date: Tue, 25 Jun 2013 11:35:42 +0200	[thread overview]
Message-ID: <20130625093542.GR11309@8bytes.org> (raw)
In-Reply-To: <FA29E63A-76F3-4F53-8945-59E47BC8C4E4@yahoo.ca>

Hi James,

On Tue, Jun 25, 2013 at 12:12:53AM -0600, James Georgas wrote:
> I discussed the issue with an LSI engineer, and he said that since the
> integrated controller uses system memory, which it gets from the BIOS
> during initialization, there will be issues with the IOMMU. I assume
> he is referring to DMA address problems due to IOMMU translation.

Looks like the problem is in the LSI driver. The driver needs to dma-map
the system memory it gets from the BIOS (for example with dma_map_single)
and use the dma_handle returned for transactions. Otherwise the IOMMU
will block the accesses from the device and make it unusable.


	Joerg



      reply	other threads:[~2013-06-25  9:35 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-06-25  6:12 Integrated MegaRAID controller and AMD IOMMU issue James Georgas
2013-06-25  9:35 ` Joerg Roedel [this message]

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