[HD2 Android Q&A, Help & Troubleshooting and Genera] aussiebum:
Heavy standby power drain workaround for SOME builds!

Alright, out of interest I downloaded a copy of each of the more recent Android builds just to see the setup of each one's /system/lib/hw/light.* layouts.

NOTE: This might just be a problem with froyo-based 2.2 builds. Dunno if it makes a difference on 2.1 builds. Again, DO NOT bother trying this if Current Widget doesn't report high batt usage (1 min poll time) during standby/screen off! High standby drain being ~60ma or so.

NOTE 2: To get comparable standby power drain results, please turn off Auto Sync, Background Sync, Bluetooth and Wifi in Settings but leave 3G connectivity ON. ALL my reported battery drain figures are performed with those settings.

Builds checked:

Mattc1.7ppp

Bangsters1.1

HyperDroid1.1

shubCRAFT1.5RealStockRMNET

From anecdotal evidence of browsing each of the build threads, Mattc and Bangsters (and some of the newer builds like SuperHD2) builds APPEAR to have great battery life (ie. no problems caused by the light libraries).

So I checked HyperDroid1.1 and shubCRAFT1.5 and for potential key problems and sure enough, in both of these builds, they appear to use the newer "patched" lights.qsd8k.so dated around mid-August. Mattc's and Bangsters DON'T (or use a different library?).

Conclusion?

The mid-August dated /system/lib/hw/lights.qsd8k.so is (possibly) buggy and causing higher battery drain during standby.

Backup your Android build before you experiment just in case it hangs or blows up your phone or something.

POSSIBLE Fix/workaround for battery drain due to buggy light hw libraries:

REPLACE the file /system/lib/hw/lights.qsd8k.so with the "original" android one and REBOOT for changes to take effect.

IF the high standby drain problem still exists, that means there's probably another lights.qsd8k.so somewhere under /system/lib/... replace that too (as reported by some Shubcraft 1.5 users)

If connected to a PC, use Droid Explorer. If not, use some kind of file explorer with root access permissions on your phone - like Root Explorer, or ES File Explorer.

In HD2Froyo V2, this means deleting the current lights.qsd8k.so and renaming lights.qsd8k1.so to lights.qsd8k.so.

In Shub's and Hyperdroid, REPLACE the mid-August dated lights.qsd8k.so with one from one of the other froyo-based builds. As a example, I've attached the one extracted from my HD2Froyo V2 build to this post.

Mattc's 1.7ppp doesn't appear to need this fix. I get 11ma on standby/screen off, which is basically normal.

I've tested against the file I attached against Shub's 1.5 realstock rmnet briefly and I get... 8ma on standby. this is with Michyprima's r8 kernel and fresh install (ie. no other crap running the background). Notification led doesn't work properly anymore though as a result of this fix... it flashes green (and goes away after awhile).

(04/Sept/10): IF standby power drain suddenly jumps back to 60ma (from 5-6ma or whatever), TURN OFF "Use GPS Satellites" in Android Settings (or via a widget), or reboot. It seems there is a bug whereby turning on wifi and using it / using Market (current suspects so far) and then turning wifi off afterwards triggers high standby battery drain unless GPS is disabled. Investigating this some more.

(04/Sept/10): Also, when starting Android, make sure keypad lights are on. This does seem to help with ensuring low standby power drain. It also still confirms imo that the customised hardware libraries used to control keypad / led notification lights for our HD2's are still buggy and need further dev work to fix.

EDIT 3: IF you still get ****e battery drain, check that you've also done the Windows Mobile Registry edits for enabling MicroSD card power management. Do a forum google search for the cab/thread...

EDIT: the filesize is irrelevant since it appears to differ based on whatever the chef uses as base build.

EDIT 2: Fixed the download link... no longer have to rename the file!