You have been subscribed to a public bug: There is a system with the Silicon Motion SM750 graphics chip. In the kernel it supported by the sm750fb driver. Xorg server uses fbdev driver to work with it.
The graphics works on Ubuntu LTS 18.04.2, but after updating to Ubuntu 18.04.3 the fbdev driver stops detecting the device. Without output devices, the Xorg server terminates with error 1. How to reproduce: * Update Ubuntu 18.04.2 to version 18.04.3/18.04.4. or * Boot from Ubuntu Desktop livecd: 18.04.3/18.04.4 LTS, 19.04, 19.10, 20.04 LTS. After many tests, I found: 1. This problem occurs after upgrading the Xorg server to version >= 1.20.2. 2. Building the fbdev driver from the source package "xserver-xorg- video-fbdev-hwe-18.04" without the patch <revert-ae0aeffae665746.diff> solves the problem. Tested with Xorg 1.20.5 (Ubuntu 18.04.4 LTS), 1.20.8 (Ubuntu 20.04 LTS). Starting with version 1.20.2, Xorg includes a commit [1] (it is the parent for the release commit [2]) that fixes the same "regression in 0.5.0 caused by ae0aeffa" issue as the patch <revert-ae0aeffae665746.diff> in the driver source package. [1] https://cgit.freedesktop.org/xorg/xserver/commit/?id=f5dc787fc9bb102e4eea477d1817e35370084ea2 [2] https://cgit.freedesktop.org/xorg/xserver/commit/?id=2a0c6c15c35cd262e7cdb86dcc43cb1aeb714c8e ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: xserver-xorg-video-fbdev-hwe-18.04 1:0.5.0-1ubuntu1~18.04.1 ProcVersionSignature: Ubuntu 5.3.0-46.38~18.04.1-generic 5.3.18 Uname: Linux 5.3.0-46-generic x86_64 ApportVersion: 2.20.9-0ubuntu7.14 Architecture: amd64 Date: Wed Apr 29 15:32:52 2020 InstallationDate: Installed on 2020-04-28 (0 days ago) InstallationMedia: Ubuntu 18.04.2 LTS "Bionic Beaver" - Release amd64 (20190210) SourcePackage: xserver-xorg-video-fbdev-hwe-18.04 UpgradeStatus: No upgrade log present (probably fresh install) ** Affects: xserver-xorg-video-fbdev (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug bionic disco eoan fbdev focal -- [regression] Graphics mode does not start on Silicon Motion SM750 chip beginning with Ubuntu 18.04.3 https://bugs.launchpad.net/bugs/1875859 You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-fbdev in Ubuntu. _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp
