Problem with starting X: drm:r128_cce after upgrade to 5.1

[Alexey Chuprinin]

Hello

I've upgraded to 5.1 from 5.0. Now I can't start X.
I rebuild X collection via ports, but it doesn't help.
In messages.log I have a lot of lines like:
kernel: error: [drm:r128_cce_start] *ERROR* r128_cce_start called without lock held
kernel: error: [drm:r128_cce_idle] *ERROR* r128_cce_idle called without lock held
kernel: error: [drm:r128_cce_reset] *ERROR* r128_cce_reset called without lock held

In XFree86.0.log:
(EE) R128(0): R128CCEWaitForIdle: CCE idle -1007
(EE) R128(0): Idle timed out, resetting engine...
(EE) R128(0): R128CCEWaitForIdle: CCE reset -1007
(EE) R128(0): R128CCEWaitForIdle: CCE start -1007

After running X I can't switch to any console neither close X, the only way
is rebooting computer.

I will be appreciated for any help.

Alexey