Hello, thank you for the reply. In the meantime I have done some tests and I managed to build Bluez 5.49 on 12.04 with 3.4.0 kernel without much issues (except Dbus 1.6 dependency, but that is easy to solve by building it from source). I also successfully managed to build Pulse 7.1 and vendor drivers for the BT Dongle. After lot of trial and error it came out that removing of the rtl8723bu_config from /lib/.../firmware directory solves the issue with HSP. It is probably some kernel specific issue as on another machine with newer kernel it works all together. Now we can use the BT headsets in HSP mode, new Bluez improved the compatibility with many headsets and new Pulse with NEON support consumes considerably less CPU. So we are happy with the setup now :) Best regards, Petr -----Original Message----- From: Ramya BM <m.ramya@xxxxxxxxxxxxxxxxxx> Sent: Wednesday, January 16, 2019 7:30 AM To: Kazda, Petr <Petr.Kazda@xxxxxxxxxxxxxxxx> Cc: linux-bluetooth@xxxxxxxxxxxxxxx Subject: Re: Bluez4 HSP problems -> backporting of Bluez5 to Ubuntu 12.04 Hi Petr, >> Now to the main question. Is it possible to backport Bluez5 to Ubuntu 12.04? We do not need the GUI elements, just the basic modules (BLE, HID, audio). Yes it is possible to configure bluez5 on ubuntu 12.04. Regards, Ramya ----- Original Message ----- From: "Petr Kazda" <Petr.Kazda@xxxxxxxxxxxxxxxx> To: linux-bluetooth@xxxxxxxxxxxxxxx Sent: Thursday, 10 January, 2019 15:05:19 Subject: Bluez4 HSP problems -> backporting of Bluez5 to Ubuntu 12.04 Dear Bluez developers, we have a product that is currently build using OMAP4 platform with Ubuntu 12.04 (armhf build) running on it. Due to various reasons the upgrade to more recent version of Linux is not possible (mainly because TI does not provide updated OS image and sources for proprietary drivers). So we are stuck with Bluez 4.101 (latest available version built from sources). We have been testing compatibility with two Bluetooth headsets - Jabra Steel and Plantronics Explorer 55. Neither of these works in HSP mode, Plantronics does not work even in A2DP. We are using Edimax EW-7611ULB dongle. More specifically Jabra works in A2DP, in HSP it does not show any errors anywhere, but it simply does not transfer any sound in or out. Plantronics does not work in A2DP (there is message like failed to acquire transport bluez_XXXXXXXX from pulseaudio), in HSP it throws error in btusb module. I tried every possible workaround found on the internet, tweaked the settings back and forth, tried different combinations, but no luck. I came to the conclusion that it might be somehow connected with SCO packets routing, but at this point I do not see any way how to move further by myself. I tested both devices with more recent Ubuntu 18.04 with the same Edimax dongle, same drivers and both headsets work without issues, so it seems that the culprit outdated Bluez. Now to the main question. Is it possible to backport Bluez5 to Ubuntu 12.04? We do not need the GUI elements, just the basic modules (BLE, HID, audio). If it is theoretically possible, is there anyone willing to do it (even as a paid job)? Thank you. Petr Disclaimer:- The information contained in this electronic message and any attachments to this message are intended for the exclusive use of the addressee(s) and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately and destroy all copies of this message and any attachments. The views expressed in this E-mail message (including the enclosure/(s) or attachment/(s) if any) are those of the individual sender, except where the sender expressly, and with authority, states them to be the views of GlobalEdge. Before opening any mail and attachments please check them for viruses .GlobalEdge does not accept any liability for virus infected mails.