This last patch (0001-drm-radeon-exclude-system-placement-when-validating)
creates a full Xorg freeze:
Form xorg.log:
[   207.780] (WW) RADEON(0): flip queue failed: Invalid argument
[   207.781] (WW) RADEON(0): Page flip failed: Invalid argument
Repeated many times

>From kern.log:
[  207.595082] radeon 0000:01:00.0: efaa7000 pin failed
[  207.595096] [drm:radeon_crtc_page_flip] *ERROR* failed to pin new rbo buffer
before flip
[  207.595434] [drm:radeon_cs_ioctl] *ERROR* Failed to parse relocation -22!
[  207.601745] [drm:radeon_cs_ioctl] *ERROR* Failed to parse relocation -22!
[  207.602094] radeon 0000:01:00.0: efaa7000 pin failed
Repeated many times

I'm going to git pull to latest and try building again... Does it depend on
some other patch?