https://bugzilla.kernel.org/show_bug.cgi?id=198123
Peter Gazer (ttallink@googlemail.com) changed:
What |Removed |Added ---------------------------------------------------------------------------- CC| |ttallink@googlemail.com
--- Comment #50 from Peter Gazer (ttallink@googlemail.com) --- Simply adding a 10ms msleep call in radeon_crtc_load_lut completely fixes the issue for me, so yes, race condition for sure (HD 6850 card).
Let me know if there's anything else I can try to nail down the actual issue, I'd like to find a proper patch for this.