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Bluetooth hot plug support almost there

January 11, 2020 — BarryK

You can follow the chain of posts regarding Bluetooth audio support in EasyOS, previous post:

The very cheap USB Bluetooth dongle that I ordered, a mere AU$4.89, has arrived:


It is recognized when plugged in, and running "lsusb" identifies it:

Bus 003 Device 003: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)

However, its controller (adapter) cannot be found. The dongle has "CSR 4.0" printed on it, but it is not actually a cambridge Silicon Radio chip, it is an inferior Chinese clone chip. This page explains: also has a link to a patch, to recognise some of the clone chips. The author found the patch worked, but Bluetooth connection kept dropping out.

I have compiled the 5.4.10 Linux kernel, with that patch. Unfortunately, no go, the controller is still not recognized.

Hot-plugging itself does work, when I plug in the dongle, the Bluetooth tray applet appears, unplug the dongle and dongle and the applet disappears. That much is good, we just need a Linux-compatible dongle to test with.

I have ordered another one from eBay, the pictures are the same, labelled with "CSR 4.0", but more expensive, AU$8.99 AU stock, but the page states that it works with Linux. Perhaps it is a different Chinese clone chip, one for which the patch does work?

That should arrive next week, however, I have decided to build Easy version 2.2.3 and upload it, English only, for anyone who would like to test Bluetooth audio, and if you have a dongle to try, that will be great.

One other thing: on that post where I reported on the goodies ordered:


...the Bluetooth ear-pieces have arrived. Yes, they work, but mono only. same thing on my Huawei phone. That is disappointing. Is that a known limitation with the very cheap ear-pieces? 

Tags: easy