https://bugs.freedesktop.org/show_bug.cgi?id=40699
Summary: KMS on Thinkpad W500: no picture on external monitors with DisplayPort, but DVI works. Product: DRI Version: XOrg CVS Platform: x86-64 (AMD64) OS/Version: Linux (All) Status: NEW Severity: normal Priority: medium Component: DRM/Radeon AssignedTo: dri-devel@lists.freedesktop.org ReportedBy: andreas.wallberg@gmail.com
Hi all!
I have troubles connecting my Thinkpad W500 running Arch Linux 64-bit to external monitors via DisplayPort (DP) while using Kernel Mode Setting (KMS) and a recent kernel (3.0.4). KMS + DP appears to be broken. The laptop has a ATI Radeon HD 3650 chip.
I have tried two monitors: the HP ZR22w and the Eizo EV2333W.
HP ZR22w ========
When KMS+DP is used on boot, I get this error message on the HP ZR22w:
Input signal Out of Range Change Settings to 1920 x 1080 - 60Hz
Inside X11, I am unable to get the screen going when KMS+DP is used. xrandr reports the screen being connected and that 1920x1080 is being sent to it. I still have the same error message.
If I turn off KMS, the monitor works just fine with DP and X11 and xrandr do their jobs but I obviously lose all the niceties with KMS.
If I use a DP->DVI adaptor and instead use the DVI connector on the monitor, KMS works just fine.
However, using the 2.6.35 kernel in Fedora 14, KMS + DP works just fine.
Eizo EV2333W ============
The same behavior as reported for the HP is true on the Eizo EV2333W monitor, but the latter provides more informative dialogs.
Using the old Fedora 2.6.35 kernel and KMS+DP, the monitor shows this info about the video signal on the Information dialog:
DisplayPort 1920x1080 fH: 76.5kHz fV: 59.9Hz
Using a 3.0.4 kernel in Arch and KMS+DP, the monitor shows:
Signal Error DisplayPort fD: 111.1MHz fH: 50.5kHz fV: 44.8Hz
The "44.8" on the last line is read so there is obviously something wrong with the signal here.
My guess is that the EDID handling is broken somehow on DP. I have tried adding various video= switches in grub to force the resolution but I am not really sure how apply them to the DisplayPort (unable to find any documentation on this) or whether it matters since the problem seems to be that the kernel is unaware it sends an incorrect video signal to the monitor.
The only reference I have found to this monitor and KMS is this one, but I am not sure what to make of it: http://www.spinics.net/lists/dri-devel/msg13061.html
I would much appreciate any pointers! What logs and config files would you like to follow up on this?