Battery life with the latest drm

[Jan Kokemüller]

On 04.02.2015 21:27, Lars Engels wrote:
> By the way on the X230 (IvyBridge i7) the loader.conf setting
> "drm.i915.enable_rc6=7" makes a huge difference.
> For some other reason I removed it from loader.conf and
> hw.acpi.battery.time showed 160 minutes. After re-adding it battery time
> went up to 230 minutes.

I've been using the same setting for a while now and can confirm the 
increase of battery life. It also makes a huge difference in fan noise 
on my T420.

Can you suspend/resume with rc6 on? I had to patch around a deadlock in 
i915_irq.c: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=183859
I haven't checked yet if this still occurs after the recent drm import.