Am Wed, 12 Feb 2014 15:32:20 +0200 hat Grazvydas Ignotas notasas@gmail.com geschrieben:
Hi,
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
Ah, okay, I'll check that tonight then!
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.
Okay... so it's still our slow Xorg and SDL then.
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.
Hmm, but it doesn't really seem to clock down when doing nothing. I'll try what it does when X is not running, just at the CPU core.
Do you know what happens when you use both cores? Do they run at the same clockspeed or can one run with 1,5GHz and the other with 0,5GHz?
Running PSX emulation uses 70% on one core, the other core doesn't do much (though Linux sometimes seems to move the tasks around, so the 70% are sometimes on one then on the other core).
So if both cores are clocked higher even though just one core is being used actually, that would also increas power usage.
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..
Hmm... but even on lower resolutions moving X Windows around seems a lot slower than on the Pandora, so something is different 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..
Yes - is it that much different on the OMAP5 than on the OMAP3? I thought TI stuff is pretty similar, so we might be able to use it on the OMAP5 with minor changes.