i915 rc6 powersaving on ironlake failing

[Fernando Herrero Carrón]

Hi everyone,

I am running FreeBSD 11.0-RELEASE-p2 #0 on an old toshiba laptop. I have
had drm.i915.enable_rc6=7 on /boot/loader.conf for a long time (at least in
10-RELEASE) and I thought it was working.

I have only realised now the following error in dmesg:

drmn0: taking over the fictitious range 0xc0000000-0xd0000000
error: [drm:pid813:__wait_seqno] *ERROR* WARN ON:
!ring->irq_get(ring)error: [drm:pid813:ironlake_enable_rc6] *ERROR* failed
to enable ironlake power power savings

I don't know if it is a regression in FreeBSD 11 or if I just never noticed
the error before. Is there anything I can do to enable powersaving?

Thanks,
Fernando