What makes bluetooth hardware detected in slackware 13.37?

sylye · 06-27-2013, 11:42 AM

Hi,

Just a question out of curiosity.

I bought a combo of bluetooth keyboard and mouse yesterday, but I forgot I have used dm-crypt to encrypt most of my partition (/usr, /var, /home), so the system will prompt for password to decrypt in the middle of rc.S If the bluetooth keyboard didn't get recognized before that, I will not able to boot smoothly.

When I plugged in the two devices today, I am amazed all runs well and the bluetooth keyboard is well detected in the middle of rc.S (which let me input the dm-crypt password) and I able to boot into X without any problem, and the bluetooth mouse detected perfectly as well.

I found out I actually
- didn't enable /etc/rc.d/rc.bluetooth to be executable
- /sbin/modprobe bluetooth is not turned on in /etc/rc.d/rc.modules
- result of 'lsmod|grep bluetooth' gives me

Code:

bluetooth              47805  0 
rfkill                 13278  1 bluetooth

- content of /etc/modprobe.d/bluetooth.conf gives me:

Code:

options btusb reset=1

- the following is found in my /boot/config:

Code:

CONFIG_BT=m
CONFIG_BT_L2CAP=m
CONFIG_BT_SCO=m
CONFIG_BT_RFCOMM=m
CONFIG_BT_RFCOMM_TTY=y
CONFIG_BT_BNEP=m
CONFIG_BT_BNEP_MC_FILTER=y
CONFIG_BT_BNEP_PROTO_FILTER=y
CONFIG_BT_CMTP=m
CONFIG_BT_HIDP=m
CONFIG_BT_HCIBTUSB=m
CONFIG_BT_HCIBTSDIO=m
CONFIG_BT_HCIUART=m
CONFIG_BT_HCIUART_H4=y
CONFIG_BT_HCIUART_BCSP=y
CONFIG_BT_HCIUART_ATH3K=y
CONFIG_BT_HCIUART_LL=y
CONFIG_BT_HCIBCM203X=m
CONFIG_BT_HCIBPA10X=m
CONFIG_BT_HCIBFUSB=m
CONFIG_BT_HCIDTL1=m
CONFIG_BT_HCIBT3C=m
CONFIG_BT_HCIBLUECARD=m
CONFIG_BT_HCIBTUART=m
CONFIG_BT_HCIVHCI=m
CONFIG_BT_MRVL=m
CONFIG_BT_MRVL_SDIO=m
CONFIG_BT_ATH3K=m

My question is: which part of the system is responsible to make the bluetooth keyboard working perfectly well during rc.S ? The bluetooth modules didn't enabled in /etc/rc.d/rc.modules but why it's still able to be loaded ? Is it something to do with udev ?

Any sharing will be much appreciated or any hints on which direction I should look into in order to understand it. Thanks

[I am using slackware 13.37 ]

STDOUBT · 06-27-2013, 08:16 PM

I don't have the answer to your question, but am curious about why you choose to use 13.37.
For me, 13.37 was one of those "golden releases" and I'm thinking about going back to it.

sylye · 06-30-2013, 02:51 AM

hi STDOUBT,

No any special reason for still using 13.37, just that I haven't had time to upgrade it to 14.0 . I believe all slackware release are equally good, isn't it ?

So anybody who is familiar with hardware initialization could shed me some light on the bluetooth thing ? I found out the bluetooth keyboard even already detected during my lilo selection screen (I have dual boot).

STDOUBT · 06-30-2013, 01:16 PM

Hmm.
Well, my thought on this is your BT devices are actually using USB interface yes?
So it's not a matter of software, or modules loading (other than USB), but simply USB HID (Human Interface Device) wherein the RF (Radio Frequency) takes the place of the wire.
Much more simple and "low-level" than it seems.

sylye · 07-03-2013, 05:00 AM

Yeah, I think your logic makes a lot of sense. Yes my bluetooth keyboard is using a USB receiver plugged at the machine. So the USB receiver got the power from the machine and takes care all of the other bluetooth thing without bother even with the OS hardware initialization. So no any BT related kernel or module thing needed here. Quite valid explanation.

Thanks for the hint