From: Joerg Roedel Date: Fri, 19 Dec 2008 13:42:12 +0000 (+0100) Subject: AMD IOMMU: reset command buffer pointers manually X-Git-Tag: v2.6.27.11~4 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8fb9f8d889b104a9acebaff83b637bcc56706576;p=pandora-kernel.git AMD IOMMU: reset command buffer pointers manually Upstream commit cf558d25e5c9f70fa0279c9b7b8b4aed7cae9bd4 Under special circumstances the IOMMU does not reset the head and tail pointer of its command ringbuffer to zero when the command base is written. This causes the IOMMU to fetch random memory and executes it as an command. Since these commands are likely illegal IOMMU stops fetching further commands including IOTLB flushes. This leads to completion wait errors at boot and in some cases to data corruption and kernel crashes. Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman --- Reading git-diff-tree failed