kernel-packages team mailing list archive

[Thomas Meyssonnier <1402196@xxxxxxxxxxxxxxxxxx>]

Okay, I found the bug goes less severe as soon as kernel 3.13.2, which is to say I bisected kernels from 3.18.0 down only to find this was mostly fixed a long time since. The bug for duplex is more severe in older versions, causing jackd to crash in 3.13.2 while 3.18.0 only has continuous xruns. That tells me they're actually working on it continuously since then; it is actually a major issue for linux audio since it's about having proper usb interfaces for laptops. I've seen quite a lot of work about that from someone called Clemens Ladisch.
So I might track down the exact commit that solved it for one-way communication, but I guess the person working on that knows all about it... pretty useless then.

Best regards,
TM

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https://bugs.launchpad.net/bugs/1402196

Title:
  Behringer UMC404 USB2 audio interface disconnects when initialized

Status in linux package in Ubuntu:
  Incomplete

Bug description:
  My audio interface, a Behriger UMC404, disappears from both lsusb and
  /proc/asound/cards as soon as I start jackd (JACK 2). This results in
  jackd failing because the card is missing. It reports a "protocol
  error" which I think refers to the USB link. See attached syslog
  messages. The card does not show up at all in Pulseaudio. Also, this
  card works just fine on my desktop, the bug only occurs on my laptop.

  Thanks,
  TM

  ProblemType: Bug
  DistroRelease: Ubuntu 14.04
  Package: linux-lowlatency 3.13.0.43.50
  ProcVersionSignature: Ubuntu 3.13.0-43.72-lowlatency 3.13.11.11
  Uname: Linux 3.13.0-43-lowlatency x86_64
  ApportVersion: 2.14.1-0ubuntu3.6
  Architecture: amd64
  AudioDevicesInUse:
   USER        PID ACCESS COMMAND
   /dev/snd/controlC1:  tmeysson   3178 F.... pulseaudio
   /dev/snd/controlC0:  tmeysson   3178 F.... pulseaudio
  CurrentDesktop: XFCE
  Date: Sat Dec 13 14:39:46 2014
  HibernationDevice: RESUME=UUID=be114ffc-be9c-47e3-b2b6-7f49c90f9931
  InstallationDate: Installed on 2014-12-03 (10 days ago)
  InstallationMedia: Ubuntu-Studio 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.1)
  MachineType: Hewlett-Packard HP EliteBook 840 G1
  ProcFB: 0 inteldrmfb
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-43-lowlatency root=UUID=20e973d8-558f-476d-9979-54c79133177e ro quiet splash vt.handoff=7
  RelatedPackageVersions:
   linux-restricted-modules-3.13.0-43-lowlatency N/A
   linux-backports-modules-3.13.0-43-lowlatency  N/A
   linux-firmware                                1.127.10
  SourcePackage: linux
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 09/03/2014
  dmi.bios.vendor: Hewlett-Packard
  dmi.bios.version: L71 Ver. 01.21
  dmi.board.name: 198F
  dmi.board.vendor: Hewlett-Packard
  dmi.board.version: KBC Version 15.55
  dmi.chassis.asset.tag: 5CG446445Q
  dmi.chassis.type: 10
  dmi.chassis.vendor: Hewlett-Packard
  dmi.modalias: dmi:bvnHewlett-Packard:bvrL71Ver.01.21:bd09/03/2014:svnHewlett-Packard:pnHPEliteBook840G1:pvrA3008CD10003:rvnHewlett-Packard:rn198F:rvrKBCVersion15.55:cvnHewlett-Packard:ct10:cvr:
  dmi.product.name: HP EliteBook 840 G1
  dmi.product.version: A3008CD10003
  dmi.sys.vendor: Hewlett-Packard

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