Re: [PATCH] iommu/amd: Add workaround to propery clearing IOMMUstatus register

From: Joerg Roedel
Date: Tue Apr 09 2013 - 13:30:37 EST


On Tue, Apr 09, 2013 at 09:22:58AM -0500, Suthikulpanit, Suravee wrote:
> The reason I implemented the "per-thread IOMMU handling" and the
> "workaround" together in one patch
> is because it simplifies the synchronization of clearing and
> checking the interrupt enabling bits.
> In the previous implementation, we could end up having multiple
> threads trying to access the status register
> at the same time.

This is the reason for the iommu->lock spinlock in this code at the
moment.


Joerg


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