On Wed, Aug 01, 2012 at 11:08:19AM +0100, James Bottomley wrote:
On Wed, 2012-08-01 at 09:58 +0100, Chris Wilson wrote:
On Wed, 01 Aug 2012 09:45:04 +0100, James Bottomley James.Bottomley@HansenPartnership.com wrote:
On Wed, 2012-08-01 at 09:16 +0100, Chris Wilson wrote:
On Wed, 01 Aug 2012 09:06:12 +0100, James Bottomley James.Bottomley@HansenPartnership.com wrote:
I got the attached to apply and it doesn't really improve the idle power much (12.5W).
That's good to know. Next step is to try overriding i915.semaphores. Can you please test with i915.semaphores=0 and i915.semaphores=1?
There's not much point doing i915_semaphores=1 since that's the default on gen 6 hardware, but i915_semaphores=0 recovers and idle power of ~6.5W
It is only the default if iommu is off, and changing the default was one of the side-effects of the patch you bisected.
Can you please login to the desktop, let it idle, record /sys/kernel/debug/dri/0/i915_cur_delayinfo and .../i915_drpc_info. Then trace-cmd record -e i915 sleep 10s, and follow up with a new pair of /sys/kernel/debug/dri/0/i915_cur_delayinfo and .../i915_drpc_info.
This will let us see whether the pm counters are truly advancing and what activity the driver is performing whilst idle.
OK, so here it is
James
Hm, if I haven't botched the math, you have a rc6 residency of about 320 seconds between the two cats of drpc_info. Can you please script this so that we have exactly 10s in between? (Aside: 3.6 has a neat interface for rc6 residency in sysfs ...)
Also, you need to attach the output of trace-cmd report (like with perf), so that we see the tracepoints in detail.
Another quick thing to confirm: What is the power consumption on the old kernel when booting with i915.i915_semaphores=1?
Thanks, Daniel