Kernel Bug Tracker – Bug 48791
i915 doesn't reach RC6 state after s2ram - Thinkpad T420, X220
Last modified: 2014-03-04 12:55:42 UTC
I'm observed sometimes hot temperature at my ThinkPad T420 (i5-2540M CPU) w/ integrated intel graphic (i0915 module) after wakeup from s2ram.
Powertop-2.1 shows that the GPU is at 100% - seems that the RC6 state isn't reached any longer.
S2ram again helüs.
BTW 3.5.x is fine -
I can confirm this on 3.6.2 with Archlinux on a Thinkpad X220 Tablet with an i7-2620M.
Furthermore it happens both under a RHEL 64 bit kernel and a stable Gentoo x86 system.
With 3..6.3 this issue becomes more and more annoying. About 50% of all reboots yields into a system with hot CPUs (86 °C) and a fan running at high speed.
I have to s2ram the system and to wakeup it to get a normal state back.
Please could somebody point me to a /sys or /proc file where the current state is stored. I'm planning to add a warning to my s2ram/s2disk acpi scripts about this to avoid over-heating/fan-damage at my system.
Trying out the patches mentioned there. The patch at https://bugs.freedesktop.org/show_bug.cgi?id=54089#c26 didn't work so far.
patches don't help /can't be applied - will close this a s a dup
*** This bug has been marked as a duplicate of bug 48721 ***
due to https://bugzilla.kernel.org/show_bug.cgi?id=48721#c36 probably neither dup nor solved.
This behavior can be confirmed with newer versions of PowerTOP which displays GPU state statistics on the second tab. For reference, I'm using version 2.20.17 of the intel xf86 driver.
(In reply to comment #8)
> This behavior can be confirmed with newer versions of PowerTOP which displays
> GPU state statistics on the second tab. For reference, I'm using version
> 2.20.17 of the intel xf86 driver.
A simple script is :
if [[ $A -eq $B ]]; then
if [[ -n "$ACTION" ]]; then
* RC6 issue
Lukas Hejtmanek who commented on this bug: https://bugs.freedesktop.org/show_bug.cgi?id=54089
Seems to have exactly the same problem.
It may be some interaction of kernel and graphics driver. I'm running the 3.4 series at the moment with xf86-video-intel-2.20.17. There the problem does not occur. If I upgrade to a recent 3.8 rc then it does happen.
I'm not sure if the patch mentioned in the linked bug already landed in that particular graphics driver. It was added to Gentoo on Jan 10th.
It may be that this patch here solves the issue for me. So far it looks good:
OK, whatever my issue is, I reproduced it with 3.8-rc4 and the patch from bug 52411.
reproduced it with a Thinkpad X220 Tablet, Core i5-2520M, kernel 3.8.0-rc5, GPU 100% active in powertop and /sys/class/drm/card0/power/rc6_residency_ms
Interestingly I reproduced the issue with my "backup" kernel 3.4.24 too. With this kernel powertop does not show the rc6 state, but it seems very likely that this is the same issue: On a small fraction of resumes the power usage spikes (20W instead of 9W) and going through another suspend/resume cycle solves the problem (with reasonable probability).
If anyone tells me what to do to narrow it down further, I'll be happy to help. Because of the low frequency with which the problem happens, bisecting seems to be out of reach.
(In reply to comment #14)
> Interestingly I reproduced the issue with my "backup" kernel 3.4.24 too
Interesting - I'm pretty sure I didn't observed a high power consumption during my v3.4.x usage (I'd definitely realized that b/c of the noisy fan of my ThinkPad T420) - and b/c v3.6 was released in Oct 2012 and I closely follow the mainline this means that there's a chance that this behaviour was backported with a stable patch after that.
Said that something between v3.4.12 and v3.2.24 could contain this bug ?
I can't exclude the backporting of the problem! For long time I used 3.4.2 where I can't remember to have noticed the problem (but I'm not 100% sure, my fan is silent).
FWIW I tried this (for 3.7.6 queued) patch :
applied on top of 3.7.5 at a stable Gentoo but w/o success.
Even more with 3.7.5 I do now run into this issue at nearly every boot phase and after s2disk (however not after s2ram)
I think this bug is related to https://bugzilla.kernel.org/show_bug.cgi?id=52411
I don't know how to mark this bug as being related.
(In reply to comment #18)
> I think this bug is related to
> I don't know how to mark this bug as being related.
Just like that, for example. ;)
However, Toralf says in comment #17 that the commit that fixed bug 52411 did not fix this one for him.
(In reply to comment #19)
> However, Toralf says in comment #17 that the commit that fixed bug 52411 did
> not fix this one for him.
Right - and to make it clear - it fails w/ s2ram too, but not every time (and not every reboot is affected) - however - if I run into this issue eg. after an s2ram, then I have to s2ram again *and* have to wait few seconds. If I immediately after s2ram do wake up my system then the issue appeared again.
FWIW, can't reproduce this with X220T running 3.8.0-rc7.
could this points to the culprit : https://lkml.org/lkml/2013/2/12/5 ?
Huh? Your link is about the CPU, our problem here is the GPU (and was not present for me before the 3.5 series)
I'm running 3.8.0-RC7 on an X220 and I think I'm still seeing this issue.
powertop says my GPU is ~70% in active state when the system is idling :/
(In reply to comment #24)
> I'm running 3.8.0-RC7 on an X220 and I think I'm still seeing this issue.
> powertop says my GPU is ~70% in active state when the system is idling :/
Not reaching rc6 at all (like in this bug report) is not the same as reaching 30% rc6.
Please try the patch at https://bugs.freedesktop.org/attachment.cgi?id=74922&action=edit
(In reply to comment #26)
> Please try the patch at
It would not apply against 3.7.9 :
sudo patch -p1 --dry-run < /home/tfoerste/devel/0001-drm-i915-Fix-SNB-RC6-init-sequence.patch
patching file drivers/gpu/drm/i915/i915_reg.h
Hunk #1 succeeded at 4140 (offset -41 lines).
Hunk #2 succeeded at 4210 (offset -43 lines).
Hunk #3 succeeded at 4226 with fuzz 2 (offset -43 lines).
patching file drivers/gpu/drm/i915/intel_pm.c
Hunk #1 succeeded at 2479 (offset -117 lines).
Hunk #2 FAILED at 2605.
Hunk #3 FAILED at 4475.
2 out of 3 hunks FAILED -- saving rejects to file drivers/gpu/drm/i915/intel_pm.c.rej
Woke my 3.8.0-1-rc7-mainline-dirty X220 machine from suspend this morning and GPU is 100% active.
vanilla-3.8.0 still suffers from this
(In reply to comment #25)
> Not reaching rc6 at all (like in this bug report) is not the same as reaching
> 30% rc6.
Is there a bugzilla/launchpad/whatever for that issue, somewhere? I've been stuck with 3.3.8 for months as it's the last power-friendly kernel for ThinkPad T420. :-(
I tried kernel 3.8.8 in a samsung series 5 and it seems that the problem is still present.
I also noticed that if I turn the laptop on and I take some time to login, it will enter in the same condition, with the GPU not going to rc6.
w/ 3.8.8 I didn't observed it any longer here at a ThinkPad T420 with integrated intel graphic (only). - and with 3.9.0 in addition I did not observed it (yet).
Can you please all test whether
improves the rc6 behaviour?
issue is back here on a stable 32 bit Gentoo Linux, somewhere in 3.9.2-3.9.4 it started again IMO.
got hit again by the bug after resuming from ram. another s2r cycle turned it back to normal.
Linux 3.10.0-rc2-JJ #1 SMP PREEMPT Tue May 21 16:50:48 CEST 2013 x86_64 Intel(R) Core(TM) i5-2520M CPU @ 2.50GHz GNU/Linux
I can confirm that this happens way more often on 3.9.4 than it did on 3.9.0 and 3.9.2. Also, I've been running 3.9.4+https://patchwork.kernel.org/patch/2481431/ for the last 21 hours and I hit the problem just now. So no, it doesn't help, I'm afraid. :-(
Confirmed and reproduced with various 3.6+ kernels on Thinkpad T520, i7-2640M, i915 only, on Fedora. I've stayed on Fedora 17 and started building my own late series 3.4.x kernels to avoid this. Currently no issue on the following. Thankfully the issue has not been back-ported to 3.4:
Linux retro 3.4.48-1.dek.fc17.x86_64 #1 SMP Mon Jun 10 18:34:02 PDT 2013 x86_64 x86_64 x86_64 GNU/Linux
(In reply to comment #38)
I don't think so, governor problems occurred at my system completely independendly from this issue much more later.
(In reply to comment #38)
I checked out 15239099d7 and reverted that particular commit - issue does still exist - seems not to be related.
Please retest with 3.13 - we've improved the rc6 and rps logic considerably and it should now be much more robust at entering low-power states on idle systems.
(In reply to Daniel Vetter from comment #41)
> Please retest with 3.13 - we've improved the rc6 and rps logic considerably
> and it should now be much more robust at entering low-power states on idle
evee 3.12.6 is much more stable than before - did no longer observed this since 3.12.x at all
confirming issue on 3.11.7
cpu does not descend into rc states until machine is suspened, alternates between 8W and 30W as a result.
Kernel command line contains 'i915.modeset=1 i915.i915_enable_rc6=4 i915.i915_enable_fbc=1 i915.lvds_downclock=1 pcie_aspm=force intel-audio-powersave=true' to no effect.