From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Williamson Subject: Re: Regression in kernel 4.2.3+ (relative to 4.1.10) on AMD 990FX system with IOMMU enabled Date: Wed, 04 Nov 2015 14:08:11 -0700 Message-ID: <1446671291.3692.147.camel@redhat.com> References: <563A3F64.50808@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <563A3F64.50808-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Laine Stump Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: iommu@lists.linux-foundation.org On Wed, 2015-11-04 at 12:24 -0500, Laine Stump wrote: > Last week I upgraded my Fedora 22 AMD 990FX system from kernel 4.1.10 to > 4.2.3 (standard Fedora builds) and multiple devices stopped working: > > * 00:14.2 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 > Azalia (Intel HDA) (rev 40) > > * 02:00.[01] Ethernet controller: Intel Corporation 82576 Gigabit > Network Connection > > * 01:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Cedar > HDMI Audio [Radeon HD 5400/6300 Series] > > (The 1st is integrated on the motherboard, the 2nd & 3rd are behind an > AMD RD890 pci-pci bridge. There may be other devices failing, but these > are the ones immediately obvious.) > > Whatever is the source of the failure, it ends up that the drivers for > these devices aren't loaded. > > At Alex Williamson's suggestion, I tried disabling IOMMU in the BIOS, > and magically all the devices resumed normal operation (except that I > can't do vfio device assignment because the IOMMU is disabled). > > Reverting to kernel 4.1.10 very definitely eliminates the problem. I've > also tried kernel 4.2.5 and it has the same problem as 4.2.3 (these > three are the only pre-built kernels for F22). I can provide dmesg / > lspci output from each of these, or any other debug info anyone might > like me to gather. I built a 4.2.3 kernel for my 990fx system and can't seem to reproduce it. Does 'lspci -k' for those devices show any driver? Does 'lsmod' show the drivers loaded, igb and snd_hda_intel? If not, does manually modprobe'ing either of those drivers change anything? You haven't installed a script that writes to driver_override or setup a configuration where those devices are claimed by pci-stub and forgotten about it, have you? (it's happened to me) Otherwise, dmesg is probably a good place to start. Thanks, Alex