Idle optimization

[levi]

Simply amazing! Since updating and rebooting, the light on my USB wifi nubbin now goes out when I turn off USB host, TV-out continues to work (but I guess that doesn't actually use ext power), and my battery life meter has gone up by almost two hours on my 20% full battery (that's about twice as long!).

I'll have to see what it reckons the total battery time is after I've recharged it overnight. Not that the meter is likely to be especially accurate until it's learned what the runtime looks like.

 

[levi]

Woo! 92% charge and it reckons I'll get over 32 hours of runtime!

I use my tv-out only Pandora to listen to music on the move (I've configured various keyboard shortcuts to control things), and it's a pain when I'm away from home if I forget to charge my Pandora one night, and it shuts down on me, losing my place in the music file (I'm still working on getting deadbeef to load immediately on login). If it does last over 24 hours, it means it should last until the next morning!

 

[joachim]

As a Slackware user I sometimes use a DVB-T stick for recording. I would like to stop
the stick to use energy after recording. Is there an easy way to do this, maybe with a bash script ?

 

[levi]

Well, the opkg update primarily seemed to be a kernel update, as far as I could see. Does slackware use the same kernel as SZ?

 

[Linux-SWAT]

Thanks notaz !

 

[rygD]

and my battery life meter has gone up by almost two hours on my 20% full battery (that's about twice as long!).

I got the update at around 23%, and upon rebooting with 20% I had more than doubled my time according to live sys info (a little over 4.5 hours).

Woo! 92% charge and it reckons I'll get over 32 hours of runtime!

I haven't checked mine since charging, but that sounds great. I hope aggressive power saving like this is the default for the Pyra from early on.

(I'm still working on getting deadbeef to load immediately on login).

There are a couple things I keep telling myself I will eventually get to load upon login (live sys info being the main one) and I still haven't done it.

 

[levi]

Yeah, I put a shell script in ~/.config/autostart to call pnd_run on the deadbeef PND, but looking in the log file it seems to start but segfault a short way into setup. Perhaps there's some process that needs to be established before graphics can be displayed - next thing to do is to add a shortish sleep to the script, but it might be nice to know what process needs to be up and running so I can first wait for it, and be a bit more robust.

 

[notaz]

As a Slackware user I sometimes use a DVB-T stick for recording. I would like to stop
the stick to use energy after recording. Is there an easy way to do this, maybe with a bash script ?

USB host is controlled by the ehci_hcd kernel module, so "modprobe ehci_hcd" when you want to enable USB host and "rmmod ehci_hcd" to disable.
[doublepost=1464033792,1464033471][/doublepost]

Woo! 92% charge and it reckons I'll get over 32 hours of runtime!

That's with just TV out enabled? Out of interest, how much runtime it used to have before?

 

[rygD]

I supposedly will get about 20 hours of light use with 95%+ charge (I was playing Burger Time and it stayed around there).

 

[levi]

That's with just TV out enabled? Out of interest, how much runtime it used to have before?

That's right; wifi, usb host, bt off, tv out on. The runtimes I've seen in the past varied quite a bit, but somewhere between about 12 hours and 16 hours seemed common.

 

[PokeParadox]

That's right; wifi, usb host, bt off, tv out on. The runtimes I've seen in the past varied quite a bit, but somewhere between about 12 hours and 16 hours seemed common.

Sounds like you really lucked out with your battery!

 

[levi]

That's good, because my screen is atrocious and right nub pretty unreliable
[doublepost=1464049193,1464047555][/doublepost]Okay, just connected it to the TV again to see where it's at before I head to bed; 12 hours at 53%, after a waking day spent mostly idle with 1 hour listening to music in deadbeef. That's heading for a shorter runtime than initially estimated, but it's a first test only, and it's still predicting to still be running by morning, so that's an improvement.

 

[notaz]

You could bind a key to disable tv-out when it's not connected, it will allow the SoC to fully idle.

Or perhaps the screen saver should not only disable LCD, but also TV-out?
I'm a bit unsure if that's won't break somebody's workflow.

 

[rygD]

screensaver?

 

[notaz]

screensaver?

Yeah, the standard Xorg one that turns off the LCD after 10 minutes of inactivity (by default).

 

[levi]

Disabling tv out on screen saver might make issues like the issue we had with the emulators which went into low power mode once the screensaver kicked in if you were playing using an external joystick easier to diagnose.

The fact tv out doesn't blank once the screensaver kicks in does mean that it'll tend to burn an image in on TVs that are susceptible to that, so that's another point in favour.

The only users I can see who are disturbed by this are likely to be those who use their pandora as some media server with display by the TV out and controlled by an external joystick, but I can't see how many of those users there are. If it were possible for the screensaver to watch USB/bluetooth joysticks as well as keyboard and mouse, that would fix it for them and also stop the issue with the emulators occurring. They'd see their display blank, but it reappear once they touched the joystick.

But I'd be perfectly happy if you just leave it as is. Even with the code as is, my unit had 18% charge left after 24 hours, which is good enough for me. I might investigate adding a hotkey to deadbeef to run the TV out switch script, but for anyone who doesn't depend on TV out, they can just leave it switched off and hopefully get even longer runtimes than I do.

 

[lukey]

Nice!
With your latest Updates, WiFi On (But WiFi LED turned off), "ondemand" cpufreq Govenor, Lid Closed, XChat, Claws-Mail(Which scans for new mail every 30 Minutes) (Both use the Bluetooth LED for notifications) and my IRC Bot, I have ~48Hours remaining Battery runtime @76% (When I shortly open the Lid and look at the xfce Battery Gauge).

Edit: Oh and add palemoon "killall -STOP"ed to the list.

 

[_jr_]

Does loading the g_cdc module (by itself without having anything connected to the port) have an impact on power usage?

 

[Bachstelze]

Really nice improvement.
Out of curiosity could someone compile powerstat for the pandora? http://kernel.ubuntu.com/~cking/powerstat/
I tried the dchrt chroot environment, but make/gcc/g++ produce a segfault at compile time.

Main reason to run powerstat is to have a second C State Graph, as the cpu c state diagram of the system info behave weird in low power mode. There all time is graphed to C0.

 

[joachim]

@ notaz : thanks for the good job. I tried rmmod which switched off the hub, but you told
you also switched off the 5V somehow. How can I do this ? Mostly when I record from DVB-T afterwards I do a ffmpeg job which is running some hours. So I want to switch off the 5V to save battery. And maybe I can do a bash script to switch on USB and 5V just before the recording ? I have a GHz model.Is the USB 5V switched off when shutdown (My PC still has power on USB when shut off).

Thanks for help.