-   Slackware - ARM (
-   -   Slackware ARM Bluetooth on the RPi3 & 4 (

Exaga 08-06-2019 12:32 PM

Slackware ARM Bluetooth on the RPi3 & 4

Originally Posted by wowbaggerHU (Post 6020786)
The Bluetooth hci0 interface is still absent however both on my PI3B+ and on my PI4.

Yes, I'm not surprised. I found some strange things on the Raspberry Pi 4. I noticed there was a module or three missing from the SARPi4 kernel. This caused Bluetooth not to initialise.

So, I rebuilt the RPi4 kernel/modules and included everything needed to run this Bluetooth shizzle. Installed the new stuff. Logged into the system and...


root@torq:~# hciconfig
hci0:  Type: Primary  Bus: SDIO
        BD Address: 00:00:00:00:00:00  ACL MTU: 0:0  SCO MTU: 0:0
        RX bytes:0 acl:0 sco:0 events:0 errors:0
        TX bytes:0 acl:0 sco:0 commands:0 errors:0

The BT hci0 interface was there but it was in a 'DOWN' state. NO WAY was this thing changing. No matter what I tried, I just couldn't get it up! :scratch:


root@torq:~# hciconfig hci0 up
Can't init device hci0: Input/output error (5)

Oh, wait a minute! This BT interface is on the SDIO bus!?!? It needs to be on UART.

The problem appears to be that the 'btsdio' module is loading before the 'hci_uart' module. So the module that loads first 'becomes resident', if you get what I mean. With the 'btsdio' module active you aren't allowed to dethrone or oust it.

So, I solved this by removing the damned 'btsdio' module thing [temporarily] and...


root@torq:~# rmmod btsdio
root@torq:~# hciattach ttyS0 bcm43xx 921600
Cannot open directory '/etc/firmware': No such file or directory
Patch not found, continue anyway
Set Controller UART speed to 921600 bit/s
Device setup complete
root@torq:~# hciconfig
hci0:  Type: Primary  Bus: UART
        BD Address: AA:AA:AA:AA:AA:AA  ACL MTU: 1021:8  SCO MTU: 64:1
        RX bytes:668 acl:0 sco:0 events:34 errors:0
        TX bytes:423 acl:0 sco:0 commands:34 errors:0

root@torq:~# hciconfig hci0 up
root@torq:~# hciconfig
hci0:  Type: Primary  Bus: UART
        BD Address: AA:AA:AA:AA:AA:AA  ACL MTU: 1021:8  SCO MTU: 64:1
        UP RUNNING
        RX bytes:1378 acl:0 sco:0 events:74 errors:0
        TX bytes:1186 acl:0 sco:0 commands:74 errors:0

root@torq:~# hcitool dev
        hci0    AA:AA:AA:AA:AA:AA

Now the BT hci0 interface is up on UART bus. Time to test and see if we can see another BT device in our vicinity...


root@torq:~# hcitool -i hci0 scan
Scanning ...
        AB:CD:EF:12:34:56      iMob

That's a relief! It found 'iMob' which is my iPhone. So I should be able to connect to it...


root@torq:~# gatttool -b AB:CD:EF:12:34:56 -I
[AB:CD:EF:12:34:56][LE]> connect AB:CD:EF:12:34:56
Attempting to connect to AB:CD:EF:12:34:56
Error: connect error: Connection refused (111)
[AB:CD:EF:12:34:56][LE]> exit

Oh well, maybe I'll play with that some other time. Like never. :D

Now to see if there's any LE devices detected...


root@torq:~# hcitool lescan
LE Scan ...
09:EE:D4:A0:C3:44 (unknown)
3E:72:48:13:61:67 (unknown)
F3:33:BF:65:8B:DA (unknown)
F3:33:BF:65:8B:DA B4E5532D310C33AEE9
40:CB:C0:B6:64:EE (unknown)
40:CB:C0:B6:64:EE (unknown)
52:1C:28:E0:51:06 (unknown)
52:1C:28:E0:51:06 (unknown)
73:7A:E7:53:57:65 (unknown)
73:7A:E7:53:57:65 (unknown)
D0:03:4B:57:88:87 (unknown)
D0:03:4B:57:88:87 (unknown)
13:3E:65:51:B4:87 (unknown)
6D:88:34:44:4A:44 (unknown)
7E:6C:A4:10:12:AA (unknown)
21:7C:3A:DE:22:03 (unknown)

There looks to be plenty. So...


root@torq:~# hcitool leinfo F3:33:BF:65:8B:DA
Requesting information ...
Could not create connection: Connection timed out

OK. Apart from connecting to Bluetoothy things, everything seems to be working [after a fashion]. I haven't used the Bluetooth stuff on 'X' desktop, but that's what might be missing here.

These new SARPi4 image and packages with the added 'missing' kernel modules are available here:

I haven't checked the Raspberry Pi 3 BT shizzle yet but chances are it's in the same state as the RPi4 kernel was. I will make that the next job.

Exaga 08-06-2019 12:50 PM

Forgot to mention...

To enable Bluetooth at boot, add this to your /boot/config.txt file...


# Uncomment to enable Bluetooth LE

I also tested by blacklisting the 'btsdio' module but it turned out to be quite detrimental to the system.

Any problems, please let me know.

Exaga 08-12-2019 08:08 AM

As far as the Raspberry Pi 3 and 4 Bluetooth goes...

On Slackware ARM -current the on-board wireless and Bluetooth adapters are working.

On Slackware ARM 14.2 the on-board wireless adapter is working but the Bluetooth adapter is failing to initialise. After ~3 days of playing with it and trying to find a solution, life really is too short.

Use/install Slackware ARM -current. Everybody should think about switching to it anyway. If not already using it.

All times are GMT -5. The time now is 11:19 AM.