After upgrading from oneiric to precise the wireless on this machine became very slow due to an extremely large number of CTS timeouts. This is being caused by commit adb5066 (ath9k_hw: do now apply the 2.4 ghz ack timeout workaround to cts) in the kernel, which shortened the CTS timeout for ath9k chipsets. Reverting the commit gets performance back to the rates seen in oneiric.
ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: linux-image-3.2.0-12-generic 3.2.0-12.21
ProcVersionSignature: Ubuntu 3.2.0-12.21-generic 3.2.2
Uname: Linux 3.2.0-12-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
AplayDevices:
**** List of PLAYBACK Hardware Devices ****
card 0: Intel [HDA Intel], device 0: ALC269VB Analog [ALC269VB Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
ApportVersion: 1.91-0ubuntu1
Architecture: amd64
ArecordDevices:
**** List of CAPTURE Hardware Devices ****
card 0: Intel [HDA Intel], device 0: ALC269VB Analog [ALC269VB Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: sforshee 1687 F.... pulseaudio
Card0.Amixer.info:
Card hw:0 'Intel'/'HDA Intel at 0xf5cf8000 irq 45'
Mixer name : 'Realtek ALC269VB'
Components : 'HDA:10ec0269,1043841c,00100100'
Controls : 16
Simple ctrls : 9
Date: Thu Feb 2 11:26:04 2012
EcryptfsInUse: Yes
HibernationDevice: RESUME=UUID=b25224d2-a78d-4b49-b936-5f505ceafa29
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Alpha amd64 (20110705.1)
MachineType: ASUSTeK Computer INC. 1215N
ProcEnviron:
PATH=(custom, no user)
LANG=en_US.UTF-8
SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-12-generic root=UUID=a4d57f60-a7b7-4e8d-ab5f-47b8ed14d3ab ro quiet splash vt.handoff=7
RelatedPackageVersions:
linux-restricted-modules-3.2.0-12-generic N/A
linux-backports-modules-3.2.0-12-generic N/A
linux-firmware 1.68
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 12/20/2010
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 0605
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: 1215N
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: x.xx
dmi.chassis.asset.tag: 0x00000000
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK Computer INC.
dmi.chassis.version: x.x
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr0605:bd12/20/2010:svnASUSTeKComputerINC.:pn1215N:pvrx.x:rvnASUSTeKComputerINC.:rn1215N:rvrx.xx:cvnASUSTeKComputerINC.:ct10:cvrx.x:
dmi.product.name: 1215N
dmi.product.version: x.x
dmi.sys.vendor: ASUSTeK Computer INC.
I'm currently working with the upstream developers to identify an appropriate fix for this issue. I'll give this a day or so to pan out, and if no progress is made I'll submit a patch to revert that commit for precise.