From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lu Baolu Subject: Re: No video output on 4.19-rc1 on Dell XPS 13 9360 Date: Sun, 9 Sep 2018 10:01:17 +0800 Message-ID: <89dff474-7baa-83ce-d70d-fffc4699d3ce@linux.intel.com> References: <20180908165747.16c2843c@fire.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180908165747.16c2843c-STI+9kRLTpF82hYKe6nXyg@public.gmane.org> Content-Language: en-US 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: Dmitrii Tcvetkov Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: iommu@lists.linux-foundation.org Hi, The fix has been posted here. https://lkml.org/lkml/2018/9/8/14 Best regards, Lu Baolu On 09/08/2018 09:57 PM, Dmitrii Tcvetkov wrote: > I've sent the email[1] before to iommu and lkml mailing lists only, but > according to iommu mailing list archive it wasn't received[2]. I'm > resending it to Lu Baolu and Joerg Roedel with proper kernel .config > file. Sorry if the duplication is unnecessary. > > Since 4.19-rc1 my laptop boots with vertical static set of rows of dots > on the screen instead of proper video output. SSH'ing into it allowed > to get dmesg-without-pt.log output, PCI device 00:02.0 is VGA > compatible controller: Intel Corporation HD Graphics 620 (rev 02) > > Appending "iommu=pt" to kernel cmdline allowed to boot with functional > graphics, but gave dmesg-with-pt.log output. > > Bisect between v4.18 and v4.19-rc1 tags led me to commit > a7fc93fed94b173e2 (iommu/vt-d: Allocate and free pasid table). > > Reverting this commit allows to build kernel on current master > (a12ed06ba2d3fa60e), which boots with functional graphical output > without specifying "iommu=pt". > Dmesg output is in dmesg-with-revert.log. > > Without the revert current master boots like 4.19-rc1. > > [1] https://lkml.org/lkml/2018/9/7/1081 > [2] https://lists.linuxfoundation.org/pipermail/iommu/2018-September/date.html >