[Nexus 7 Android Development] sgt. meow:
8. FAQ

1. How do I enable logger? What about hso and ppp_async?

Ans:

For builds with modules:

Download the modules zip. Unzip them to you sdcard, and note the path. Fire up the Terminal. Issue these commands one by one:

su
insmod /path/to/logger.ko (only in V2)
insmod /path/to/hso.ko
insmod /path/to/cifs.ko
insmod /path/to/ppp_async.ko

To check whether they are working (they are, don't worry):

lsmod

Should output something like

logger.ko 54334 [permanent] ... blah.

You can also try:

dmesg | grep "logger"
dmesg | grep "hso"

ppp_async doesn't show any message.

To disable hso.ko and ppp_async.ko (you can't disable logger.ko once it's insmod'ed, but a simple reboot will rmmod it):

rmmod hso.ko
rmmod ppp_async.ko

For builds without modules:

To enable logger (it is off by default), issue this command in Terminal Emulator

echo "1" > sys/kernel/logger_mode/logger_mode

To disable it, just echo 0 instead.

2. Why won't my device reach 51MHz even though it's listed in the frequency list?

Ans: I have set the min rate for G cores to 102MHz. 51MHz IMO is a very stupid frequency in that it will do nothing basically. Even my 3 year old cellphone doesn't stay at 51MHz. It should be a LP core frequency (it actually was) but since Franco's hotplug driver doesn't call on the LP core, it's not reachable.

3. How do I control minimum - maximum backlight through sysfs?

Let me begin by saying that this feature is highly experimental. I can tell though that it works.

Okay so in /sys/module/board_grouper_panel/parameters you'll see two files:

min_bl - Write in a reasonable value preferably at least 30 less than max_bl. Default is 10. Not safe. Switch to 11.

max_bl - Write in a reasonable value preferably at least 30 more than min_bl.

This is what happens. *takes deep breath*

When your brightness is greater than zero but less than the min_bl, it gets changed to the min_bl. And when it's greater than max_bl, it's changed to max_bl. Otherwise it's just normal brightness levels (where's the fun in that, right? :))

PLEASE DON'T WRITE THE VALUES OF min_bl OR max_bl WHILE YOU'RE HIGH, DRUNK OR JUST DOWNRIGHT BAT-CRAP CRAZY!

There's no limit to the madness that may happen as a result.

4. How do I configure sweep2wake and doubleetap2wake? What exactly are they?

Sweep2wake and doubletap2wake are basically two versions of the same thing - they wake your device up after you have put it to sleep (not metaphorically) without using the physical buttons on the side. This is still slightly buggy. If at first it doesn't work. Touch the screen once and then tap it twice.

For sweep2wake/sleep you basically swipe along the bezels (not on the bezels though) where the soft keys would be.

For doubletap2wake, just tap twice on the screen during sleep, and it should wake up.

To configure sweep2wake go to /sys/android_touch and open up sweep2wake

0 = disbaled

1 = sweep2wake/sleep

2 = sweep2sleep

To configure doubletap2wake go to /sys/android_touch and open up doubletap2wake

0 = disabled

1 = enabled

To configure shortsweep go to /sys/android_touch and open up shortsweep

0 = disabled.

1 = enabled.

This drains battery a little faster than stock would, so yeah. Don't use it (i.e. disable it) if you want to save battery, or set up a script.

There is also a wake_timeout file. It holds the time that the dt2w wakelock will remain active after the screen is suspended.

NOTE: s2w wakelock times aren't configurable and it will stay on for 15 seconds after the screen has been suspended.

Insert the time in seconds. (60 = 1 minute; 3600 = 1 hour)

If both are disabled no wakelocks are registered and held.

5. How do I get USB OTG to work?

Go to /sys/kernel/usbhost.

echo 0 to usbhost_fixed_install_mode.

I haven't tested (hostmode, and fast charge/hostmode charge) this myself, so feedback is appreciated.

You need StickMount unless your ROM supports native OTG.

6. Why is SELinux disabled?

To get it booting on some Kit Kat ROMs. Booting in permissive may work, but I haven't tested it yet.

8. Why is my device so awesome now?

OH STAHP IT YOU! And you weren't reading carefully enough, otherwise you would have pointed out that I missed #7.

69. <== LOL!11eleventy!!1! How do I configure baseband wakelock timeout?

Go to /sys/module/baseband_xmm_power/parameters and open up the bb_timeout file.

0 means the wakelock will be held for 1 second after it is acquired.

Values are in seconds.

I used timeout instead of disabling it completely because, although there have been no problems reported, thus far, to arise from this modification, it's better to be safe (not disabling completely but making it timeout after a while) than sorry (losing functionality although it seems unlikely)

9. A POST ON RECOMMENDED SETTINGS AND STUFF

"Interactive @ 1.5GHz and GPU @ 484MHz (or even 446MHz) + no screen wake controls (if you don't use them) should give you excellent battery life and performance. You can adjust CPU speeds too."

- sgt. meow

Idea of [MENTION=5127697]keneth_c[/MENTION]

Oh and this works awesome with the IceColdJelly AOKP ROM for Tilapia. Be sure to try it out.

Works fab on 4.3 stock. Don't believe in benchmarks though.