Broken X (DRM errors)

[Julio Merino <jmmv%julipedia.org@localhost>]

Hello,

Since I upgraded yesterday to a freshly-built -current, I can't get X
to run any more.  This is on a MacBook Pro with an ATI Radeon Mobility
X1600.

As soon as I start the X server up, the screen goes off and the
machine gets extremely sluggish.  I can still access it through the
network, but killing the X server has no effect.  Other "unrelated"
processes, like sshd and tmux, can be seen chewing incredible amounts
of CPU (presumably due to a loop in the kernel; see below).

The dmesg right before the lock up shows:

Mar 29 21:43:08 desky /netbsd: info: [drm] Setting GART location based
on new memory map
Mar 29 21:43:08 desky /netbsd: info: [drm] Loading R520 Microcode
Mar 29 21:43:08 desky /netbsd: info: [drm] Num pipes: 1
Mar 29 21:43:08 desky /netbsd: info: [drm] writeback test failed
Mar 29 21:43:08 desky /netbsd: radeondrm0: interrupting at ioapic0 pin 16
Mar 29 21:43:09 desky /netbsd: info: [drm] wait idle failed status :
0x90010140 0x00050000
Mar 29 21:43:53 desky syslogd[219]: last message repeated 63 times

Any ideas as to what change broke this?

Thanks,

-- 
Julio Merino / @jmmv