Re: [Fastboot] [patch 3/5] git-ia64 versus genirq

From: Troy Heber <>
Date: 2006-08-18 23:55:16
On 08/18/06 08:48, Zou, Nanhai wrote:
> Hi Horms,
> 	I have little knowledge of the code inside CONFIG_IA64_HP_ZX1....
> I think it stop's IOMMU controller on some HP boxes.

Yes, the code is designed to shutdown the IOMMU. The problem we're
seeing is if there are sill in-flight DMA transfers happening when we
shutdown the IOMMU an MCA will occur.

Ring now we're working on a different approach, rather than shutting
down the IOMMU completely, we're going to try to update all of the
valid pdir entries to point to a single pre-alloced page. This should
safely control all of devices with out having to shutdown the IOMMU.

> Aziz told me it is necessary to have this code to start up the second kernel.

I haven't had a chance to speak with Khalid about this approach. I'm
hoping to catch him today.

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Received on Fri Aug 18 23:51:53 2006

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