The premise is that my ignorance on BT is complete. After some investigation, it is my understanding that RFCOMM channels are to RFCOMM communication a bit like ports in TCP and UDP, with the main difference that while there are really a lot of TCP/UDP ports and some of them are reserved as "well known ports", the number of channels in RFCOMM is extremely limited, so that there cannot be well known ports. Furthermore, I understand that no one should "hardwire" RFCOMM channels and that channels should be released whenever not strictly needed.
If this understanding from myself is correct, there may be issues both in LibO and in PA. >From my understanding: - LibO and the Impress remote should not hardwire RFCOMM channel 3. I understand that they should dynamically allocate a channel and make it discoverable via SDP. - Impress should not keep binded to an RFCOMM channel all the time. There should be a visible option to switch on and off the binding (probably there should be a couple of impress remote related options in the "Slide Show -> Slide Show Settings" window, including one to fire up the BT rfcomm binding). - PA should probably similarly not hardwire channel 3 for its HSP role, but here the situation seems more complex, because it may be the case that PA needs to strive for compatibility with devices that do not play to the rules. - PA should probably have a DBUS interface to switch on and off the RFCOMM binding, so that to use an application needing RFCOMM channel 3, one does not need to take down the whole of PA. I have opened a bug on PA too. See it at https://gitlab.freedesktop.org/pulseaudio/pulseaudio/issues/827. That report is bad, because when I made it my understanding of BT was even poorer than it is now. In any case, it seems to me that the current issue could be fixed completely on the LibO side, by dynamically allocating the channel and by letting the app running on the phone discover it via SDP. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to libreoffice in Ubuntu. https://bugs.launchpad.net/bugs/1798400 Title: [upstream] Regression: cannot use impress remote over bluetooth with ubuntu bionic Status in LibreOffice: Confirmed Status in bluez package in Ubuntu: Confirmed Status in libreoffice package in Ubuntu: Confirmed Status in linux package in Ubuntu: Confirmed Status in libreoffice package in Fedora: Unknown Bug description: Trying to use the impress remote (https://wiki.documentfoundation.org/Impress_Remote) over bluetooth with libreoffice over ubuntu bionic fails. The handset errors out that it cannot connect with Libreoffice on the computer even if the bluetooth adapter on the handset and on the computer are correctly paired. This does not seem to be an issue in the Libreoffice or in the impress remote code: - I have tested also past LibO versions - The Impress remote codebase has not changed recently This used to work on the same hardware (headset and laptop) with ubuntu 16.04. Hence the issue seems to be in a regression in the ubuntu bluetooth stack. To replicate: 1) Install Libreoffice on Ubuntu bionic (either from the ubuntu repo or with the deb packages from the document fundation) 2) Assure that your computer has bluetooth 3) Install impress remote on an android handset (either from the play store of via fdroid) 4) Assure that "remote control" is enabled in impress Tools>Options>Impress>General 5) Pair the bluetooth adapters in the laptop and in the computer 6) Open a presentation on the laptop 7) Open the remote on the handset, got to the bluetooth pane see the computer there, touch it 8) See the impress remote erroring out Most likely you will also get a bluetooth error on dmesg RFCOMM server failed for LibreOffice Impress Remote: rfcomm_bind: Address already in use (98) Same issue was reported for fedora ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: bluez 5.48-0ubuntu3.1 ProcVersionSignature: Ubuntu 4.15.0-36.39-generic 4.15.18 Uname: Linux 4.15.0-36-generic x86_64 ApportVersion: 2.20.9-0ubuntu7.4 Architecture: amd64 CurrentDesktop: KDE Date: Wed Oct 17 16:57:29 2018 EcryptfsInUse: Yes InstallationDate: Installed on 2013-12-12 (1769 days ago) InstallationMedia: Kubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1) InterestingModules: rfcomm bnep btusb bluetooth MachineType: Notebook W740SU ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.15.0-36-generic root=/dev/mapper/zagar_ssd--vg-root ro quiet splash resume=/dev/zagar_ssd-vg/swap_1 acpi_backlight=vendor vt.handoff=1 SourcePackage: bluez UpgradeStatus: Upgraded to bionic on 2018-06-08 (131 days ago) dmi.bios.date: 10/02/2013 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 4.6.5 dmi.board.asset.tag: Tag 12345 dmi.board.name: W740SU dmi.board.vendor: Notebook dmi.board.version: Not Applicable dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 9 dmi.chassis.vendor: Notebook dmi.chassis.version: N/A dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr4.6.5:bd10/02/2013:svnNotebook:pnW740SU:pvrNotApplicable:rvnNotebook:rnW740SU:rvrNotApplicable:cvnNotebook:ct9:cvrN/A: dmi.product.family: Not Applicable dmi.product.name: W740SU dmi.product.version: Not Applicable dmi.sys.vendor: Notebook hciconfig: hci0: Type: Primary Bus: USB BD Address: 00:C2:C6:1A:28:71 ACL MTU: 310:10 SCO MTU: 64:8 UP RUNNING PSCAN ISCAN RX bytes:245088 acl:15156 sco:0 events:1266 errors:0 TX bytes:15571 acl:402 sco:1 commands:131 errors:0 To manage notifications about this bug go to: https://bugs.launchpad.net/df-libreoffice/+bug/1798400/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
