Bluetooth Blues

While waiting for my monitor to be replaced, I got some time to spend on fixing the bluetooth. My understanding is that the BT is controlled through GPIOs and mine uses RockChip's own controller instead of the RealTek's 8723bs wireless chip.

There is a nice thread with tool to dump the GPIO. I followed the direction to dump the GPIO and I see some related names

<4>[ 738.864604] GPIO gpio1 195 bt_default_rts
<4>[ 738.866166] GPIO gpio3 278 bt_default_wake
<4>[ 738.866188] GPIO gpio3 279 bt_default_wake_host
<4>[ 738.866234] GPIO gpio3 281 bt_default_reset

I have also identified the source file for the BT driver (board-rk3188-box.c). However, the controls does not quite match. There is an entry in the source code for powering up the BT but nothing in my gpio dump above. I tried it anyway and I noticed no difference. After a few trial and error, I gave up.

As an alternative, I tried loading the stock kernel and noticed that the BT does not come up either. It turns out that there are more than just the kernel that needs replacing. It is best to work with one unknown at a time. I tried replacing the boot.img and even the WiFi is not coming up.

So I am afraid I will have to revert to a firmware with BT works and start from there. Unfortunately, it would mean I will need to wipe my stick and lose all my customizations (I'm not very comfortable in backing up the user files or the entire stick). No pain, no gain!