On Wed, Feb 12, 2014 at 2:18 PM, Michael Mrozek EvilDragon@openpandora.org wrote:
... As power consumption never went down, I'm pretty sure there was no power management active. We just don't know at what clockspeed the 2 Cores were running right now.
We do, cpufreq is on and is switching between 500MHz and 1.5GHz, see: /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
When using the Playstation emulator (same config as on the OMAP5 devboard), power consumption goes up to about 3W (or 2,5W without the display). However, once again, the power consumption was going up and down all the time, depending on how much CPU power the PSX emulator was using.
As a reminder, PSX emulation on the OMAP5 went up to 4W, and it didn't go up and down, it stayed that way.
The config is not really comparable, on pandora the PSX emu spends almost all time on emulation, while on OMAP5 it's Xorg and SDL eating everything for copying data around, only minor CPU time is spent for actual emulation. In other words, on OMAP5 the CPU has to do much more work than on pandora because of Xorg and SDL slowness.
So if Power Management really is switched off on the OMAP5 right now and we can enable / disable cores on-the-fly, we should be pretty good here.
Well at least cpufreq is working, so I'd say it has partial powersaving.
Additionally, the XServer is still running using fbdev only, without any hardware acceleration (which will probably lower the power usage as well).
FYI we also currently have it like that on pandora, only the video overlay is accelerated on pandora and not on OMAP5. I wouldn't put too many expectetions here..
Maybe enabling power management is something we should look into soon, so we can do some real life tests with power management enabled.
Powersaving on OMAPs is extremely complicated, you know yourself how long it took to get it working on pandora..
GraÅžvydas