https://bugs.freedesktop.org/show_bug.cgi?id=35894

Summary: Displaying across 3 monitors with max resolution causes one monitor to enter power-saving mode (HD6870) Product: DRI Version: unspecified Platform: x86-64 (AMD64) OS/Version: Linux (All) Status: NEW Severity: normal Priority: medium Component: DRM/Radeon AssignedTo: dri-devel@lists.freedesktop.org ReportedBy: woogie@gmail.com

Using arandr, or KDE's RandR manager, I'm trying to adjust my display to stretch across 3 monitors. One of the monitors enters power-saving mode when I try this. Monitors are, from left to right:

DVI-1 (1680x1050 LCD) DisplayPort-1 (1920x1080 LCD) DVI-0 (1680x1050 LCD)

Configuring a desktop with all monitors set to their maximum resolution causes one of the two DVI-connected monitors to enter power-saving mode. The mouse cursor will still "disappear" into this monitor as if it were enabled. No error messages appear in either X.org.log or dmesg. It is non-deterministic as to which monitor turns off of the two DVI-connected monitors.

I can configure a desktop with, for example, 1280x1024, 1920x1080, 1280x1024 for resolutions (left to right) and all three monitors will function properly. I cannot use 1680x1050, 1280x1024, 1680x1050, as one of the DVI monitors will enter power saving mode.

I have tested, and this hardware configuration will function with the proprietary fglrx driver, and under Windows, so the card/monitors do not appear at fault.

I have tried the 2.6.38 release candidate kernels, and this feature has never functioned correctly, so I don't think it's a regression.

HARDWARE: PowerColor HD6870 AMD 1075T 12Gb RAM Asus M4A89/GTD-PRO USB3 DVI-1: LG Flatron W2242TQ DisplayPort-1: Dell UV22H DVI-0: ASUS (unknown)

OS: ArchLinux, 64-bit with: Kernel26, 2.6.38.2-1 xf86-video-ati 6.14.1-1 xorg-server 1.10.0.901-1 libdrm 2.4.24-1 ati-dri 7.10.1-1

Please let me know if I can provide any additional details. I am willing to apply patches to the kernel or other packages as needed to test.