Am 15.02.2014 um 17:19 schrieb Michael Mrozek:
Am Thu, 13 Feb 2014 19:11:41 +0200 hat Grazvydas Ignotas notasas@gmail.com geschrieben:
Hi,
The power consumption doesn't change though, so it seems the core isn't really disabled in the OMAP when doing this.
If CPU idle powersaving is working properly, power usage shouldn't actually change much compared to just idle.
Oh, is CPU idle powersaving that good that a core doesn't need anything anymore when it's not being used?
Seems like our current Power Management really is pretty simple, missing a few features.
We don't know that.. It might be just SoC parts, not CPU powersaving that's not working, at least on OMAP3 there is whole CPU/MPU power domain which probably contains various support circuitry for the CPU. That part was missing powersaving in pandora's 2.6 kernel, and as you remember the battery drain was pretty bad.
True. Right now, we're on Kernel 3.8 No idea if that patch is even included: http://marc.info/?t=137407980100008&r=1&w=2
Fixes wrong voltage settings for OMAP5...
Is TI mostly working on 3.8 or 3.11/3.12 kernels?
Well, we have a TI version of the 3.8 kernel which is much ahead of 3.12 mainline. So that might be a snipped of TI's efforts to get things fixed in mainline as well.
For the GTA04 for example we currently have about 100 deviations from mainline and try hard to get them in. Some are tried with 3.10 and have not yet appeared in 3.14... Quite a difficult business.
Nevertheless we should check if e.g. 3.12 or 3.14 mainline is a better basis for the future than continuing with a TI kernel.
For the moment for my hardware-bring-up the ti-3.8 kernel was the one with the most complete EVM support I could find. So it is always good to have it for reference :)
Maybe we should do the same for the Pyra as I did for the GTA04.
I took the 2.6.32 beagleboard kernel and modified it until I was 100% sure what the problems were and could make all hardware work. This did *not* optimize power.
In parallel Neil Brown had started with a 3.4 kernel and looked at bringing in more and more features incl. better power management. When he did come to 3.7 I ported some of the missing pieces and upgraded constantly so that we currently have a 3.12 kernel with 100% of the features. Unfortunately we lost some power management optimization. But that is planned to be fixed by 3.14 (where the device tree throws us back again...).
-- Mit freundlichen Grüßen,
Michael Mrozek
OpenPandora GmbH Geschäftsführer: Michael Mrozek
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