https://bugzilla.kernel.org/show_bug.cgi?id=42887

Summary: Garbled display on external screen when using 1920x1080 instead of 1920x1200 Product: Drivers Version: 2.5 Kernel Version: 3.3 Platform: All OS/Version: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: Video(DRI - non Intel) AssignedTo: drivers_video-dri@kernel-bugs.osdl.org ReportedBy: thejoe@gmail.com Regression: No

also reported here: https://bugs.freedesktop.org/show_bug.cgi?id=44755 and here: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-ati/+bug/915408

[Problem] i have an external monitor (1920x1200 resolution) that, when set to 1920x1080 resolution (native resolution of laptop display), garbles the screen as seen in the screenshot below. The problem doesn't happen using the catalyst driver.

https://bugs.launchpad.net/lightdm-gtk-greeter/+bug/813566/+attachment/22210...

ProblemType: BugDistroRelease: Ubuntu 11.10 Package: xorg 1:7.6+7ubuntu7 ProcVersionSignature: Ubuntu 3.0.0-15.25-generic 3.0.13 Uname: Linux 3.0.0-15-generic x86_64 .tmp.unity.support.test.0:

ApportVersion: 1.23-0ubuntu4 Architecture: amd64 CompizPlugins: [core,bailer,detection,composite,opengl,decor,mousepoll,vpswitch,regex,animation,snap,expo,move,compiztoolbox,place,grid,imgpng,gnomecompat,wall,ezoom,workarounds,staticswitcher,resize,fade,unitymtgrabhandles,scale,session,unityshell] CompositorRunning: None Date: Thu Jan 12 07:42:25 2012 DistUpgraded: Log time: 2011-07-13 10:07:59.371965 DistroCodename: oneiric DistroVariant: ubuntu ExtraDebuggingInterest: Yes, whatever it takes to get this fixed in Ubuntu GraphicsCard: ATI Technologies Inc Broadway PRO [Mobility Radeon HD 5800 Series] [1002:68a1] (prog-if 00 [VGA controller]) Subsystem: Hewlett-Packard Company Device [103c:1522]InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Release Candidate amd64 (20100419.1) MachineType: Hewlett-Packard HP ENVY 15 Notebook PC ProcEnviron: PATH=(custom, user) LANG=en_US.UTF-8ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.0.0-15-generic root=UUID=639dc488-e095-42a4-8c1f-ffb1a9299e1c ro crashkernel=384M-2G:64M,2G-:128M quiet splash vt.handoff=7SourcePackage: xorg UpgradeStatus: Upgraded to oneiric on 2011-07-13 (182 days ago) dmi.bios.date: 04/23/2010 dmi.bios.vendor: Hewlett-Packard dmi.bios.version: F.26 dmi.board.asset.tag: Base Board Asset Tag dmi.board.name: 1522 dmi.board.vendor: Hewlett-Packard dmi.board.version: 36.34 dmi.chassis.type: 10 dmi.chassis.vendor: Hewlett-Packard dmi.chassis.version: N/A dmi.modalias: dmi:bvnHewlett-Packard:bvrF.26:bd04/23/2010:svnHewlett-Packard:pnHPENVY15NotebookPC:pvr048F110000241920001530000:rvnHewlett-Packard:rn1522:rvr36.34:cvnHewlett-Packard:ct10:cvrN/A: dmi.product.name: HP ENVY 15 Notebook PC dmi.product.version: 048F110000241920001530000 dmi.sys.vendor: Hewlett-Packard version.compiz: compiz 1:0.9.6+bzr20110929-0ubuntu6 version.ia32-libs: ia32-libs 20090808ubuntu26 version.libdrm2: libdrm2 2.4.26-1ubuntu1 version.libgl1-mesa-dri: libgl1-mesa-dri 7.11-0ubuntu3 version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A version.libgl1-mesa-glx: libgl1-mesa-glx 7.11-0ubuntu3 version.xserver-xorg: xserver-xorg 1:7.6+7ubuntu7 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.6.0-1ubuntu13 version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.99~git20110811.g93fc084-0ubuntu1 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.15.901-1ubuntu2.1 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20110411+8378443-1 [reply] [-] Comment 1

discussion from freedesktop.org bug: Alex Deucher 2012-01-13 08:25:54 UTC The problem is the modeline from your monitor for the 1920x1080 mode is greater than 165 Mhz which is the current cut off for single link mode in the driver: (II) RADEON(0): Modeline "1920x1080"x60.0 172.78 1920 2040 2248 2576 1080 1081 1084 1118 -hsync +vsync (67.1 kHz)

It should work if you specify a modeline with a lower clock E.g., Modeline "1920x1080R" 138.50 1920 1968 2000 2080 1080 1083 1088 1111 +hsync -vsync [reply] [-] Comment 5

Alex Deucher 2012-01-13 08:34:21 UTC Created attachment 55557 [details] [review] possible fix

This patch against drm-next or Linus git should fix the issue. [reply] [-] Comment 6 thejoe@gmail.com 2012-01-13 08:53:54 UTC confirmed that the following sequence displays a non-garbled 1920x1080 display on the external monitor:

# xrandr --newmode "1920x1080R" 138.50 1920 1968 2000 2080 1080 1083 1088 1111 +hsync -vsync # xrandr --addmode HDMI-0 1920x1080R # xrandr 1920x1080R [reply] [-] Comment 7 Florian Mickler 2012-02-01 13:09:58 UTC A patch referencing this bug report has been merged in Linux v3.3-rc2:

commit 9aa59993e226af94088adaee993eb8cfd33ae295 Author: Alex Deucher alexander.deucher@amd.com Date: Fri Jan 20 15:03:30 2012 -0500

drm/radeon/kms: refine TMDS dual link checks [reply] [-] Comment 8 thejoe@gmail.com 2012-03-07 14:45:11 UTC I've tested against a kernel with this patch, as well as mainline kernel (both built by ubuntu kernel team), and am still seeing the same behavior. So seems like this change doesn't fix the issue.