From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: IOMMU+DMAR causing NMIs-s Date: Thu, 14 Jul 2016 10:31:06 +0200 Message-ID: <20160714083106.GQ12639@8bytes.org> References: <20160713090332.GK12639@8bytes.org> <20160713094917.GM12639@8bytes.org> <20160713101859.GO12639@8bytes.org> <20160713084830.09453584@t450s.home> <1a4c4b65-c716-08a5-af89-1b0f551024ed@hpe.com> <20160713170408.6e5d2534@t450s.home> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20160713170408.6e5d2534-1yVPhWWZRC1BDLzU/O5InQ@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: Alex Williamson Cc: Meelis Roos , David Woodhouse , iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Linux Kernel list List-Id: iommu@lists.linux-foundation.org On Wed, Jul 13, 2016 at 05:04:08PM -0600, Alex Williamson wrote: > With hpwdt disabled, can you reboot a few times and look for DMAR > faults in the dmesg to see if they're all consistent, ie. device 1e.0 > doing a read from 0xb000? Is there any correlation to radeon hanging > and one of those DMAR faults appearing in the log (you can make use of > the iLO for a serial console so you can record more of the boot than > what can be captured on the VGA console). Also, this should be an > X58-based system, which reminds me of Joerg's recent commit > a4c34ff1c029 that's intended to fix a hang on such systems. That was > included starting in v4.7-rc4, so if this is a new issue, testing > before and after that commit might be relevant. Thanks, That commit fixed a hang while the IOMMU is being initialized. This hang is different, as the IOMMU already runs. So I doubt that it fixes this problem, but it is worth a test, of course. Joerg