https://bugs.freedesktop.org/show_bug.cgi?id=50655
--- Comment #74 from Andy Furniss lists@andyfurniss.entadsl.com --- (In reply to comment #73)
Does disabling hyperZ help? Set env var R600_HYPERZ=0
No, that doesn't help.
I have just found another way to avoid it though, running with my card on "low" I can't get it to lock. Turning it up to high as I normally do and it will lock on first (but not subsequent) use of text console every time.