Description of problem:
When adding a 3rd or 4th monitor from a second card with xrandr --output ..--right-of..., Xorg.0.log throws:
"Cannot do multiple crtcs without X server dirty tracking 2 interface\n"
and errors about slave pixmap memory.
Version-Release number of selected component (if applicable):
Need 4ish monitors.
Steps to Reproduce:
1. Get 2 Radeon cards with 2 ports each (I have two 5450's with 512MB each).
2. Use a blank device/screen/screenlayout/monitor setup
3. After two monitors activate, try using xrandr to activate a third and fourth
The third monitor activates in a sketchy mode where it doesn't work. The fourth monitor refuses to activate.
Both extra monitors activate.
The problem is that xorg 1.17 or 1.18 replaced "HAS_DIRTYTRACKING2" with "HAS_DIRTYTRACKING_ROTATION" in pixmap.h and the old version of xf86-video-ati still looks for HAS_DIRTYTRACKING2. The newest version of xf86-video-ati looks for either:
#if !defined(HAS_DIRTYTRACKING_ROTATION) && !defined(HAS_DIRTYTRACKING2)
I took the spec file from xorg-x11-drv-ati-7.6.0-0.4.20150729git5510cd6.fc23.src.rpm and the source from git://anongit.freedesktop.org/xorg/driver/xf86-video-ati , connected the two, got rid of the comments with %'s in them (not sure why that's a problem), and it seems to work fine now. I'm not sure where the git5510cd6 string comes from. The version I'm using ends in:
Author: Michel Dänzer <email@example.com>
Date: Wed Jan 20 11:20:30 2016 +0900
With 4 monitors and Xinerama off, I get like 5fps, but at least it's consistent (with 2 monitors and vsync off, I can get hundreds). With Xinerama on and the old 7.6.0-0.4.20150729git5510cd6 driver, compiz-manager would stall out for up to a minute every other time a window was closed. So I'd call this an improvement, sort of, but you should still do your own testing for the 1/20 version before releasing it.
xorg-x11-drv-ati-7.6.1-3.20160215gitd41fccc.fc23 xorg-x11-drv-nouveau-1.0.12-3.fc23 has been submitted as an update to Fedora 23. https://bodhi.fedoraproject.org/updates/FEDORA-2016-caddc95794
xorg-x11-drv-ati-7.6.1-3.20160215gitd41fccc.fc23, xorg-x11-drv-nouveau-1.0.12-3.fc23 has been pushed to the Fedora 23 testing repository. If problems still persist, please make note of it in this bug report.
See https://fedoraproject.org/wiki/QA:Updates_Testing for
instructions on how to install test updates.
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2016-caddc95794
xorg-x11-drv-ati-7.6.1-3.20160215gitd41fccc.fc23, xorg-x11-drv-nouveau-1.0.12-3.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.