168c:002b ath9k wireless module interferes with low latency audio

Bug #1018220 reported by Len Ovens on 2012-06-27
8
This bug affects 1 person
Affects Status Importance Assigned to Milestone
Linux
New
Undecided
Unassigned
Ubuntu Studio Kernel
New
Undecided
Unassigned
linux-lowlatency (Ubuntu)
Low
Unassigned

Bug Description

When running Jackd at lower latencies, there are three or four major xruns every minute or so. If the wireless is connected. If the wireless is disabled it gets much worse with an xrun every 5 seconds or so. As far as I know the tx is powered off at this point. If I modprobe -r ath9k, there are no xruns.

I am not sure the wireless can be connected without causing problems, but when it is disabled and the tx turned off it should not interfere with anything. The module is able to do this if the wireless is dissabled and the machine rebooted, so there is a state when ath9k is first loaded that is fine. When the wireless is disabled it should go back to that state.

For now, I have a script that unloads and reloads the kernel module for audio work.

By the way, the xruns are worse with this version of the kernel than they were in precise (3.2 low latency kernel).

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: linux-image-3.5.0-1-lowlatency 3.5.0-1.1
ProcVersionSignature: Ubuntu 3.5.0-1.1-lowlatency 3.5.0-rc3
Uname: Linux 3.5.0-1-lowlatency i686
ApportVersion: 2.2.5-0ubuntu1
Architecture: i386
Date: Tue Jun 26 18:39:12 2012
InstallationMedia: Ubuntu-Studio 12.10 "Quantal Quetzal" - Alpha i386 (20120626)
ProcEnviron:
 LANGUAGE=en_CA:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_CA.UTF-8
 SHELL=/bin/bash
SourcePackage: linux-lowlatency
UpgradeStatus: No upgrade log present (probably fresh install)
---
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.25.
AplayDevices:
 **** List of PLAYBACK Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: ALC272 Analog [ALC272 Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
ApportVersion: 2.2.5-0ubuntu1
Architecture: i386
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: ALC272 Analog [ALC272 Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: len 1760 F.... xfce4-volumed
                      len 1778 F.... pulseaudio
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0x58340000 irq 45'
   Mixer name : 'Realtek ALC272'
   Components : 'HDA:10ec0272,1025022f,00100001'
   Controls : 17
   Simple ctrls : 9
CurrentDmesg: [ 33.443695] init: plymouth-stop pre-start process (1485) terminated with status 1
DistroRelease: Ubuntu 12.10
HibernationDevice: RESUME=UUID=f3c94466-e315-4542-9eb3-8dc577170995
InstallationMedia: Ubuntu-Studio 12.10 "Quantal Quetzal" - Alpha i386 (20120627.2)
MachineType: Acer Aspire one
Package: linux (not installed)
ProcEnviron:
 LANGUAGE=en_CA:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_CA.UTF-8
 SHELL=/bin/bash
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.5.0-1-lowlatency root=UUID=2bb7fb2c-e9fa-4187-9d00-8cf1e6597f0c ro quiet splash vt.handoff=7
ProcVersionSignature: Ubuntu 3.5.0-1.1-lowlatency 3.5.0-rc3
RelatedPackageVersions:
 linux-restricted-modules-3.5.0-1-lowlatency N/A
 linux-backports-modules-3.5.0-1-lowlatency N/A
 linux-firmware 1.82
Tags: quantal
Uname: Linux 3.5.0-1-lowlatency i686
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm audio cdrom dip lpadmin plugdev sambashare sudo
dmi.bios.date: 11/28/2009
dmi.bios.vendor: Acer
dmi.bios.version: V1.25
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: Aspire one
dmi.board.vendor: Acer
dmi.board.version: V1.25
dmi.chassis.type: 10
dmi.chassis.vendor: Acer
dmi.chassis.version: V1.25
dmi.modalias: dmi:bvnAcer:bvrV1.25:bd11/28/2009:svnAcer:pnAspireone:pvrV1.25:rvnAcer:rnAspireone:rvrV1.25:cvnAcer:ct10:cvrV1.25:
dmi.product.name: Aspire one
dmi.product.version: V1.25
dmi.sys.vendor: Acer

Len Ovens (len-ovenwerks) wrote :

Lens Ovens, thank you for reporting this and helping make Ubuntu better. I am temporarily moving this to package linux, in order to obtain relevant apport data, then will move back to linux-lowlatency.
Despite this, could you please execute the following in a terminal:
apport-collect 1018220

Regarding your Bug Description:
>"By the way, the xruns are worse with this version of the kernel than they were in precise (3.2 low latency kernel)."

So, in Precise this problem still occurred, but just less frequently?

As well, if you could also please test the latest upstream kernel available that would be great. It will allow additional upstream developers to examine the issue. Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Once you've tested the upstream kernel, please remove the 'needs-upstream-testing' tag. This can be done by clicking on the yellow pencil icon next to the tag located at the bottom of the bug description and deleting the 'needs-upstream-testing' text. As well, please comment on which kernel version specifically you tested.

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream', and comment as to why specifically you were unable to test it.

Please let us know your results. Thanks in advance.

affects: linux-lowlatency (Ubuntu) → linux (Ubuntu)
Changed in linux (Ubuntu):
importance: Undecided → Low
status: New → Incomplete

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tags: added: apport-collected
description: updated

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On Wed, June 27, 2012 4:48 am, Christopher M. Penalver wrote:
> Lens Ovens, thank you for reporting this and helping make Ubuntu better. I
> am temporarily moving this to package linux, in order to obtain relevant
> apport data, then will move back to linux-lowlatency.
> Despite this, could you please execute the following in a terminal:
> apport-collect 1018220

Done.

> Regarding your Bug Description:
>>"By the way, the xruns are worse with this version of the kernel than
>> they were in precise (3.2 low latency kernel)."
>
> So, in Precise this problem still occurred, but just less frequently?

About the same frequency, but only one xrun at a time. With the later
kernel (3.5) there would be a group of xruns each time. However, having
played with it a bit more, this may be unrelated as I have found that the
low latency performance even with the ath9k module unloaded is not as good
in general. That is, I could have a virtual midi keyboard playing qsynth
through jack at 128 frames/period with no xruns(3.2 kernel), now I get
some (3.5 kernel).

> As well, if you could also please test the latest upstream kernel
> available that would be great. It will allow additional upstream
> developers to examine the issue. Refer to
> https://wiki.ubuntu.com/KernelMainlineBuilds . Once you've tested the
> upstream kernel, please remove the 'needs-upstream-testing' tag. This

I'll do that next

--
Len Ovens
www.OvenWerks.net

tags: added: kernel-bug-exists-upstream

Sorry, but I can't find the "needs-upstream-testing" tag. I must be looking in the wrong place. I was able to put in "kernel-bug-exists-upstream" so maybe my data collection over wrote it.
The upstream kernel is:
len@ustudio1204:~$ uname -a
Linux ustudio1204 3.5.0-030500rc4-generic #201206241635 SMP Sun Jun 24 20:43:32 UTC 2012 i686 i686 i686 GNU/Linux

The problem is still there and I am reminded why UbuntuStudio has a low latency kernel, each xrun log entry from jack comes with two more errors as well:

23:21:04.309 XRUN callback (161).
Wed Jun 27 23:21:04 2012: ERROR: JackEngine::XRun: client = PulseAudio JACK Sink was not run: state = 1
Wed Jun 27 23:21:04 2012: ERROR: JackAudioDriver::ProcessGraphAsyncMaster: Process error
23:21:09.301 XRUN callback (162).
Wed Jun 27 23:21:09 2012: ERROR: JackEngine::XRun: client = PulseAudio JACK Sink was not run: state = 1
Wed Jun 27 23:21:09 2012: ERROR: JackAudioDriver::ProcessGraphAsyncMaster: Process error

I was not getting the pulse errors before.

Len Ovens (len-ovenwerks) wrote :

to be more clear, I was not getting the pulse errors with either the 3.2 or 3.6 low latency kernel while wireless was disabled.

summary: - ath9k wireless module interferes with low latency audio
+ 168c:002b ath9k wireless module interferes with low latency audio

Marking to Triaged in linux-lowlatency as non-lowlatency mainline tested, development release tested, and hardware info provided.

affects: linux (Ubuntu) → linux-lowlatency (Ubuntu)
Changed in linux-lowlatency (Ubuntu):
status: Incomplete → New
status: New → Triaged
Joseph Salisbury (jsalisbury) wrote :

This issue appears to be an upstream bug, since you tested the latest upstream kernel. Would it be possible for you to open an upstream bug report at bugzilla.kernel.org [1]? That will allow the upstream Developers to examine the issue, and may provide a quicker resolution to the bug.

If you are comfortable with opening a bug upstream, It would be great if you can report back the upstream bug number in this bug report. That will allow us to link this bug to the upstream report.

[1] https://wiki.ubuntu.com/Bugs/Upstream/kernel

tags: added: kernel-bug-exists-upstream-3.5.0-030500rc4-generic
removed: kernel-bug-exists-upstream
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