On Tue, 2012-07-31 at 10:54 +0100, Chris Wilson wrote: > On Tue, 31 Jul 2012 10:37:35 +0100, James Bottomley <James.Bottomley at > HansenPartnership.com> wrote: > > On Tue, 2012-07-31 at 09:28 +0100, Chris Wilson wrote: > > > On Tue, 31 Jul 2012 09:06:42 +0100, James Bottomley <James.Bottomley at > > > HansenPartnership.com> wrote: > > > > Actually, bad news: it looks like the problem is drm: > > > > > > > > on 3.5 killing X causes idle power to go 14W -> 5.9W > > > > on 3.4.6 killing X causes idle power to go 6.8W -> 5.7W > > > > > > The files that will be the most interesting to compare at first are: > > > > > > /sys/kernel/debug/dri/0/i915_drpc_info > > > /sys/kernel/debug/dri/0/i915_cur_delayinfo > > > /sys/kernel/debug/dri/0/i915_fbc_status > > > > This is for the good kernel 3.4.6 > > > > jejb at dabdike> cat /sys/kernel/debug/dri/0/i915_drpc_info > > RC information accurate: yes > > Video Turbo Mode: yes > > HW control enabled: yes > > SW control enabled: no > > RC1e Enabled: no > > RC6 Enabled: yes > > Deep RC6 Enabled: no > > Deepest RC6 Enabled: no > > Current RC state: RC6 > > Core Power Down: no > > jejb at dabdike> cat /sys/kernel/debug/dri/0/i915_cur_delayinfo > > GT_PERF_STATUS: 0x00000d29 > > RPSTAT1: 0x00040d00 > > Render p-state ratio: 13 > > Render p-state VID: 41 > > Render p-state limit: 255 > > CAGF: 650MHz > > RP CUR UP EI: 20459us > > RP CUR UP: 172us > > RP PREV UP: 0us > > RP CUR DOWN EI: 0us > > RP CUR DOWN: 0us > > RP PREV DOWN: 0us > > Lowest (RPN) frequency: 650MHz > > Nominal (RP1) frequency: 650MHz > > Max non-overclocked (RP0) frequency: 1100MHz > > jejb at dabdike> cat /sys/kernel/debug/dri/0/i915_fbc_status > > FBC disabled: disabled per module param (default off) > > > > And the bad kernel 3.5 > > > > jejb at dabdike> cat /sys/kernel/debug/dri/0/i915_drpc_info > > RC information accurate: yes > > Video Turbo Mode: yes > > HW control enabled: yes > > SW control enabled: no > > RC1e Enabled: no > > RC6 Enabled: yes > > Deep RC6 Enabled: no > > Deepest RC6 Enabled: no > > Current RC state: RC6 > > Core Power Down: no > > RC6 "Locked to RPn" residency since boot: 0 > > RC6 residency since boot: 97671911 > > RC6+ residency since boot: 0 > > RC6++ residency since boot: 0 > > jejb at dabdike> cat /sys/kernel/debug/dri/0/i915_cur_delayinfo > > GT_PERF_STATUS: 0x00000d29 > > RPSTAT1: 0x00048d00 > > Render p-state ratio: 13 > > Render p-state VID: 41 > > Render p-state limit: 255 > > CAGF: 650MHz > > RP CUR UP EI: 63719us > > RP CUR UP: 26us > > RP PREV UP: 0us > > RP CUR DOWN EI: 0us > > RP CUR DOWN: 0us > > RP PREV DOWN: 0us > > Lowest (RPN) frequency: 650MHz > > Nominal (RP1) frequency: 650MHz > > Max non-overclocked (RP0) frequency: 1100MHz > > jejb at dabdike> cat /sys/kernel/debug/dri/0/i915_fbc_status > > FBC disabled: disabled per module param (default off) > > Ok, that rules out the the easy case of rc6 being disabled or not > functioning at all, which could easily account for 6W. > > When did you inspect the debug files? One effect I can imagine is that > if your system was previously stuck at RPn and never upclocking the GPU > when X starts. The question would then be what is preventing the GPU > from reaching its lowest power state again.
After I logged into an xfce4 session and powertop showed idle had been reached. James
