> -----Original Message----- > From: Andreas Mohr [mailto:a...@lisas.de] > Sent: Thursday, February 14, 2013 11:33 PM > To: linux-kernel@vger.kernel.org > Cc: R, Durgadoss; Zhang, Rui; pe...@piie.net > Subject: thermal governor: does it actually work?? > Importance: High > > For me after having loaded acerhdf the fan never stops (with kernelmode > active), despite staying safely below trip point > (acerhdf_set_cur_state() actually never gets called).
Please attach the output of "grep . /sys/class/thermal/thermal_zone*/cdev*/*"? > And AFAIR in a 3.2.0 kernel acerhdf fan operation seemed to just work > (i.e., no fan for low temps, from the beginning). > Needless to say 3.2.0 didn't even feature all the modern thermal > governor crapyard yet ;) (ok, well, it's more complex but it's also a > very nice environment capability) > > 3.8-rc7: > CONFIG_ACPI_THERMAL=m > CONFIG_THERMAL=m > CONFIG_THERMAL_HWMON=y > CONFIG_THERMAL_DEFAULT_GOV_STEP_WISE=y > # CONFIG_THERMAL_DEFAULT_GOV_FAIR_SHARE is not set # > CONFIG_THERMAL_DEFAULT_GOV_USER_SPACE is not set CONFIG_FAIR_SHARE=y > CONFIG_STEP_WISE=y # CONFIG_USER_SPACE is not set # CONFIG_CPU_THERMAL > is not set > > > > Terminology in this area seems to be quite a bit off, too, at several > docs places, at least according to my understanding: > > e.g. drivers/thermal/step_wise.c has the following comment: > > /** > * step_wise_throttle - throttles devices associated with the given > zone > * @tz - thermal_zone_device > * @trip - the trip point > * @trip_type - type of the trip point > * > * Throttling Logic: This uses the trend of the thermal zone to > * throttle. > * If the thermal zone is 'heating up' this throttles all the cooling > * devices associated with the zone and its particular trip point, by > * one > * step. If the zone is 'cooling down' it brings back the performance > of > * the devices by one step. > > > > if ... heating up ... throttles ... > Sorry, but at least for P4 clockmod stuff (or some such), throttle > states (P1...P8 IIRC) meant that the CPU operation was *reduced*, i.e. > with pause intervals. For processors, surely you are right. > And the translation of throttle clearly says that it does go that way > and not the other way... > (yes, you managed to confuse me that much that I even had to look up > things to verify) > The question is that if we can also call it "throttle" when reducing the device performance to generate less heat. I do not have a clear answer for this as I'm not a native English speaker. And what you're saying here may be right. Surely I can generate a patch to rename it if throttle can't be used in that way. Len, What's your idea on this? Thanks, rui > ... cooling down ... brings back ... > This should certainly be worded "reduces" or some such. > > So, any idea why I'm missing callbacks in acerhdf (if that is what I'm > supposed to expect to happen)? > Kernel bug, .config mistake, missing/wrong user-side setup? > > Needless to say if kernel bug this ought to be fixed pre-3.8 ideally. > > Thanks, > > Andreas Mohr -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/