Flesh out post

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

content/posts/making-a-bluetooth-adapter-work-on-linux.md

@@ -4,14 +4,75 @@ date = 2020-07-17
 description = "Getting a USB Bluetooth dongle to function properly on Linux proved to be somewhat of a trip, which I'm documenting here."
 draft = true
 slug = "making-a-bluetooth-adapter-work-on-linux"
-tags = ["bluetooth", "usb dongle"]
+tags = ["bluetooth", "linux", "bt-audio"]
 title = "Making a Bluetooth adapter work on Linux"
 +++
 
 I made a couple of purchases yesterday, including a Bluetooth speaker and a USB Bluetooth dongle to pair it to my computer. Now here's a couple things that you need to know about said computer:
 
-- This runs Linux
-- It runs a customized build of the Zen kernel with a very slimmed down config
-- The computer has never had Bluetooth connectivity before
+-   It runs Linux
+-   It runs a customized build of the Zen kernel with a very slimmed down config
+-   It has never had Bluetooth connectivity before
 
-Thanks to this combination of factors, things got weird.
+Thanks to this combination of factors, things got weird. I tried a bunch of things before getting it working, so it is entirely possible that I miss some steps that were important but I didn't think so while writing this. Please let me know on [Twitter](https://twitter.com/MSF_Jarvis) if these steps didn't work for you and I'll try to fix this post.
+
+### Getting the right packages
+
+You're gonna need 1) a GUI to handle BT devices, b) the PulseAudio module for Bluetooth. For the GUI I used [blueberry](http://packages.linuxmint.com/search.php?release=ulyana&section=main&keyword=blueberry), and [pulseaudio-module-bluetooth](https://packages.ubuntu.com/focal/pulseaudio-module-bluetooth) for PulseAudio support.
+
+I did `apt install -y blueberry pulseaudio-module-bluetooth` to get these on Linux Mint, you can do whatever your distro's preferred package handling method is.
+
+### Fixing up the kernel (optional)
+
+I mentioned earlier that I run a very slimmed down config, which means nothing that I didn't already use was enabled. This included Bluetooth, so I went ahead and enabled all the configs for it [here](https://msfjarvis.dev/g/linux/992c2d8bce8b). If everything works out, your dmesg should contain these lines
+
+```shell
+$ dmesg | rg Bluetooth
+[    0.146115] Bluetooth: Core ver 2.22
+[    0.146118] Bluetooth: HCI device and connection manager initialized
+[    0.146119] Bluetooth: HCI socket layer initialized
+[    0.146119] Bluetooth: L2CAP socket layer initialized
+[    0.146120] Bluetooth: SCO socket layer initialized
+[    0.325395] Bluetooth: HCI UART driver ver 2.3
+[    0.327116] Bluetooth: RFCOMM socket layer initialized
+[    0.327117] Bluetooth: RFCOMM ver 1.11
+[    0.327117] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
+[    0.327119] Bluetooth: BNEP socket layer initialized
+[    0.327119] Bluetooth: HIDP (Human Interface Emulation) ver 1.2
+[    0.327120] Bluetooth: HIDP socket layer initialized
+```
+
+If you run your distro's kernel, you shouldn't need to make any changes.
+
+### Wrapping up
+
+If you're not a relatively up-to-date distro, you might need to make some more manual adjustments before everything works. Open up `/etc/pulse/default.pa` in any editor with root access (so you can write your changes back), then look for `module-bluetooth-discover`. In my version of the file, I have this:
+
+```pa
+.ifexists module-bluetooth-discover.so
+load-module module-bluetooth-discover
+.endif
+```
+
+It means that if the module is discovered, it will be loaded. On older versions this might just be `# load-module module-bluetooth-discover`. In that case, uncomment the line.
+
+Next, open up `/usr/bin/start-pulseaudio-x11` in the same way. Look for this:
+
+```bash
+    if [ x"$SESSION_MANAGER" != x ] ; then
+        /usr/bin/pactl load-module module-x11-xsmp "display=$DISPLAY xauthority=$XAUTHORITY session_manager=$SESSION_MANAGER" > /dev/null
+    fi
+```
+
+Below it, add `/usr/bin/pactl load-module module-bluetooth-discover` so the final result looks like this:
+
+```bash
+    if [ x"$SESSION_MANAGER" != x ] ; then
+        /usr/bin/pactl load-module module-x11-xsmp "display=$DISPLAY xauthority=$XAUTHORITY session_manager=$SESSION_MANAGER" > /dev/null
+    fi
+    /usr/bin/pactl load-module module-bluetooth-discover
+```
+
+This will manually load the module when X11 triggers PulseAudio init. This is more a hail mary, and if you want, you can test without it but it won't hurt to add it anyway.
+
+Once done, reboot your computer and you should be able to pair and connect to devices and play audio through them.