Power settings/Standby

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Description

By now, you may have noticed that the WDTV is quite hot when it runs, and it doesn't seem to get any less hot when it is in standby. This would imply that even when it is idle, it uses up a lot of unnecessary power - which means it's more costly for you and less environmentally friendly for everyone. There is a way around this excessive power consumption. The information in this post is relevant for WDTV-Live devices. It might/might not work/be applicable for other generation devices

Note: The information in this page is not necessarily useful any more, because b-rad has added the advanced standby as an option inside WDLXTV (DEEP_SLEEP) starting with firmware 0.5.1.4. You may want to use that option instead of what is here.

Note2: Here are some results when testing this on various firmwares: http://forum.wdlxtv.com/viewtopic.php?f=3&t=7321&p=61607#p61607

Power consumption

  • On, while streaming: 6-7W
  • On, no activity (screensaver): 6W
  • Default standby: 5-6W
  • Enhanced standby: ~2W

Default standby

The default standby procedure consists of:

  • Turning off leds
  • Turning off OSD
  • Stopping video out

Your attached mass storage devices will still be powered up, your network will still be up - in fact you can still connect to your device via ssh/telnet etc. Your device will wake up by pressing once the power button, or by sending a wake-on-lan packet.

Enhanced standby

Enhanced standby forces you CPU to a standby mode and thus turns off more things:

  • Turns off USB devices
  • CPU low power mode

ONLY WORKS WITH KERNEL 2.6.22.19-19-4 #7 (you can use the fff file that comes with 0.4.7.3 releases, but you will loose other features Differences between kernels).

To enable enhanced standby, execute the following commands: 

config_tool -c POWER_DOWN_ACTION10='logger -t "power_down_action" "Entering standby"; echo standby > /proc/tangoxfreq/standby'
config_tool -s

Caveats:

  • When you enter in the low power mode, your USB disks will be unmounted (or just disconnected?) and when the device wakes up from this low powered mode, it will be unable to access them (or OSD, plugins stored on the USB) until you reboot.
  • You will have to press the power button twice (or send two wake-on-lan packets) to exit this power mode - one push gets you to default standby (you can see your USB disks light up), the second push will bring you out of standby
  • If you are booting from the ext3 firmware, the device will not wake up anymore, and you need to unplug/replug power to start it again

Enhanced standby+restart

In order to fix the issue of non-working apps/OSD/plugins after you recover from Enhanced standby, there is a small tweak you can do to automatically reboot the wdtv when exiting standby. That way, you get low-power usage while in standby and full functionality when exiting standby. The price to pay is waiting about ~1m for the WDTV to boot again. To use this setup, follow these steps: 

config_tool -c POWER_DOWN_ACTION94='logger -t "power_down_action" "Preparing busybox"; cp /bin/busybox /tmp; /tmp/busybox sh /tmp/busybox logger  "Busybox test pid:$$" ; sync'
config_tool -c POWER_DOWN_ACTION95='/tmp/busybox sh  -c "(/tmp/busybox reboot -d 3 -n -f )& /tmp/busybox echo standby > /proc/tangoxfreq/standby;"'
config_tool -s

The trick is to copy the busybox binary somewhere where it won't be affected by deep sleep (even when booting through ext3). Then, you send the system in standby and immediately after you reboot (from the same shell). The effect is that the system goes to sleep, and when you press the power button again it finishes up and executes the reboot command.

ONLY WORKS WITH KERNEL 2.6.22.19-19-4 #7 (you can use the fff file that comes with 0.4.7.3 releases, but you will loose other features Differences between kernels).

Caveats:

  • You will have to press the power button twice (or send two wake-on-lan packets) to exit this power mode - one push gets you to default standby (you can see your USB disks light up), the second push will bring you out of standby The device will wake up on one POWER key press or one WOL packet
  • Waking up your device from standby will take longer, as the device has to do a full reboot.
  • If you are booting from the ext3 firmware, the device will not wake up anymore, and you need to unplug/replug power to start it again The device should wake up and reboot even if started from ext3.
  • You will loose restore points for the movies you have viewed (unless they are saved on a usb stick)

Testing

  • There is an easy way to test if you managed to get your device in a low stanby mode - touch the wdtv after a while and sense it's temperature. If it's hot - you're not in standby mode. If it's at room temperature (or at the same temperature as your hand), then you are in standby mode.

Links

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