(In reply to comment #18)
> Ah ok, I didn't know that. Thanks for the info - I'll try the option and see
> how it goes ;-)
> 
> Unrealted to the acceleration I discovered another error message in my dmesg:
> [drm:ci_dpm_set_power_state] *ERROR* ci_upload_dpm_level_enable_mask failed
> Should I report that in a new bug ? (I should really stop hijacking this
> bug, sorry)

Yes, open a new bug for the dpm stuff.  In the new bug please note whether this
is new after applying attachment 93015 [details] [review] or if this was always there.