On Wed, 2013-02-06 at 13:12 +0100, Joerg Roedel wrote: > On Tue, Feb 05, 2013 at 06:57:21AM -0700, Shuah Khan wrote: > > Thanks much. I will hang on to this test system for testing your fix. > > Okay, here is the simple fix for v3.8-rc6. I guess it is not > straighforward to port it to v3.4, but it should be doable. > > From 2ecf57c85e67e0243b36b787d0490c0b47202ba8 Mon Sep 17 00:00:00 2001 > From: Joerg Roedel <j...@8bytes.org> > Date: Wed, 6 Feb 2013 12:55:23 +0100 > Subject: [PATCH] iommu/amd: Initialize device table after dma_ops > > When dma_ops are initialized the unity mappings are > created. The init_device_table_dma() function makes sure DMA > from all devices is blocked by default. This opens a short > window in time where DMA to unity mapped regions is blocked > by the IOMMU. Make sure this does not happen by initializing > the device table after dma_ops. > > Signed-off-by: Joerg Roedel <j...@8bytes.org>
Joerg, I tested your patch on 3.8. I was able to reproduce the problem and then apply your patch to verify that the problem is fixed. This patch applies cleanly to 3.7.6, however I could not reproduce the problem on 3.7.6 without the patch. But the window exists on 3.7 as well. Your patch can be applied to 3.7.6 as is. I back-ported the patch to 3.4 and 3.0 and tested. I am sending those patches after this email. On 3.4.29 and 3.0.62 I was able to reproduce the problem and then applied the back-ported patch to verify that the problem is fixed. Thanks again for the fix. -- Shuah -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
