From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: BUG: SCSI aic7xxx driver and AMD IOMMU Date: Mon, 23 Mar 2015 16:03:04 +0100 Message-ID: <20150323150304.GQ4441@8bytes.org> References: <54E1FFFA.1060403@compro.net> <54F60D33.8090401@compro.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <54F60D33.8090401@compro.net> Sender: linux-scsi-owner@vger.kernel.org To: Mark Hounschell Cc: "linux-scsi@vger.kernel.org >> SCSI development list" , Hannes Reinecke , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org List-Id: iommu@lists.linux-foundation.org Hi Mark, On Tue, Mar 03, 2015 at 02:36:19PM -0500, Mark Hounschell wrote: > It looks like this problem is NOT a bug with the SCSI aic7xxx driver > after all. I can duplicate this BUG very easily with other hardware. > Simply removing a driver module (whether it its self, has actually > used any of the DMA API or not) that is sitting on the same pci bus > as a card that is actually using DMA will cause this. And that card > that is in use and using DMA will no longer function. It "looks and > feels" like unloading a module causes the IOMMU to improperly unmap > valid mappings. You are right, I looked into the code and found the problem. I'll post a fix for testing this week. Joerg