3.1.6 makes Intel NUC run hotter by 15-20 degrees Celsius comparing to 3.0.6

[bass63]

The idle temperature is 10-15 degrees higher on 3.1.x builds comparing to 3.0.6 on Intel NUC Celeron DCCP847DYE box (2GB RAM). Both systems are on USB stick - OpenELEC version x64-Intel.

In my environment I got 65-70 degrees on idle on 3.0.6 and 82-90 on 3.1.6. Clean installs with Ace skin, imported library and no additional plugins. When using default skin and clean install the temperature is lower, but the difference remains - up to 15 degrees higher comparing to the old version.

The CPU usage for the two cores is almost the same in both cases - 2%+20% on 3.0.6 and 4%+16% on 3.1.6. Nothing suspicious. Here are the logs for 3.1.6

Xorg.0.0.log http://sprunge.us/BAYG var/log/messages http://sprunge.us/cGga xbmc.log http://sprunge.us/PhNL

[fritsch]

Can you please boot 3.0.6 and also give the /var/log/messages? Watch especially for:

[    2.348741] [drm] Enabling RC6 states: RC6 off, RC6p off, RC6pp off

[stefansaraev]

@fritsch he posted 3.0.6 dmesg in irc earlier today. here it is:

[12:32:09] <bass63> http://sprunge.us/GLeT - it is from 3.0.6

[fritsch]

Quote from there:

[    0.413467] [drm] Enabling RC6 states: RC6 on, RC6p off, RC6pp off

We disable RC6 for Sandy bridge gt1, cause they will crash right away, when xbmc starts, full hw freeze, see this bugtracker for more info.

@bass63 You can enable it again, by editing the boot config file and add:

i915.i915_enable_rc6=1

RC6 is a powersaving mode. Let me know about your findings.

For reference: https://github.com/OpenELEC/OpenELEC.tv/issues/2008

[bass63]

Thanks! RC6 is indeed enabled on 3.0.6 and disabled on 3.1.6, according to logs I've made changes (took me a while to figure out where's the file and where to put command ;),enabled RC6 and it seems to help - the temps are close enough to what i have on 3.0.6.

And I got no crashes whatsoever, played two movies already! I think it is safe to enable this feature back by default for owners of the "hot" systems like NUC.

[stefansaraev]

thanks @bass63 so @fritsch enabling rc6 is fine with 3.10.x kernels ? if not - I would keep this issue open

[fritsch]

We explicitely disable it for intel snb gt1 cause of a whole lot of freezes with it. You can drop the relevant kernel patch, if you want and we keep that one open here.

I disable it in kernel.

[sraue]

tested on a known affected system, removing this patch and any "i915.i915_enable_rc6=0" from bootloader together with a Mesa-9.2 testbuild dont caused the originally crash anymore, so this patch is not more needed. thanks @all . will be fixed in 3.1.7 coming the next days.