I thought I should chip in to confirm that I still get occasional issues with my USB DAC, even on the current Saucy 3.11.0-12 kernel. The symptoms are identical to those that were occurring prior to the patch, however now they usually resolve by unplugging and replugging the DAC, whereas prior to the patch they never resolved.
I'm thinking there's still something not-quite-right in the kernel handling of these async audio devices. (Or possibly, these async audio devices don't always obey the USB spec perfectly in some way?) -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1136110 Title: USB Audio Codec choppy playback Status in “linux” package in Ubuntu: Fix Released Bug description: 1) The release of Ubuntu using Ubuntu 12.10 AMD64. Ubuntu 13.04 AMD64, daily build as new as 20130314. 2) The version of the package used linux-image-3.5.0-26-generic linux-image-3.5.7-03050706-generic_3.5.7-03050706.201302221435_amd64.deb http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.5.7.6-quantal/ linux-image-3.7.7-030707-generic_3.7.7-030707.201302111436_amd64.deb http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.7.7-raring/ linux-image-3.8.0-030800rc7-generic_3.8.0-030800rc7.201302081635_amd64.deb http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.8-rc7-raring/ This bug had been confirmed appearing after the following kernel upgrade step: v3.5.0-25 > v3.5.0-26 ~ v3.5.0-27 v3.5.7.5 > v3.5.7.6 ~ v3.5.7.8 v3.7.6 > v3.7.7 ~ v3.7.10 v3.8.0-rc6 > v3.8.0-rc7 ~ v3.8.5 The v3.9 branch has been affected since its very first release. v3.9-rc1, v3.9-rc2, v3.9-rc3 v3.9-rc4 are all affected. 3) What you expected to happen When using a USB DAC to play audio, the audio should be played normally without any interruption. 4) What happened instead This bug seems to affect only a certain kind of hardware, which is called "Asynchronous USB Digital Audio Codec (DAC)". It's said that such a DAC hosts the clock itself (USB Device Host). An ordinary DAC, so called "Synchronous USB DAC", uses the clock hosted by the mother board, which is not affected by this bug. When this bug affects an asynchronous USB DAC, the audio played by the DAC is constantly interrupted. The playback itself does not stop, but the output becomes discontinous, filling with constant crackling noises, destroying everything the DAC plays. Using CLI command grep device.buffering to get the buffer from the devices, those affected kernels are reporting back a different number to the unaffected devices. The choppy noise is very similar to the situation when buffer size is not correctly set. I have tested four USB DACs, two Asynchronous and two Synchronous. Only the Asynchronous ones are affected by this bug. Affected Devices: Arce MDAC5 Arce MDAC mini Ayre Acoustics QB-9 Dragonfly USB DAC Musical Fidelity v2 DAC USB Audio Streaming Controller on affected devices: Texas Instrument TAS1020 http://www.ti.com/product/tas1020 Audio DAC on affected devices: Texas Instruments PCM1742 http://www.ti.com/product/pcm1742 This bug had been confirmed appearing after the following kernel upgrade step: 3.5.0-25 > 3.5.0-26 3.5.7.5 > 3.5.7.6 (and all 3.5.7.x above) 3.7.6 > 3.7.7 (and all 3.7.x above) 3.8.0-rc6 > 3.8.0-rc7 (and all 3.8.x above) I used Kdiff to find the similar patches, and find the following patches suspicous: USB: XHCI: fix memory leak of URB-private data (appeared in 3.5.7.6/3.7.7/3.8.0-rc7) USB: EHCI: fix for leaking isochronous data (appeared in 3.7.7/3.8.0-rc7) usb: Prevent dead ports when xhci is not enabled (appeared in 3.5.7.6/3.7.7/3.8.0-rc7) usb: Using correct way to clear usb3.0 device's remote wakeup feature (appeared in 3.5.7.6/3.7.7/3.8.0-rc7) USB: EHCI: remove ASS/PSS polling timeout (appeared in 3.7.7/3.8.0-rc7) USB: EHCI: unlink one async QH at a time (appeared in 3.7.7/3.8.0-rc7) USB: EHCI: fix timer bug affecting port resume (appeared in 3.5.7.6/3.7.7/3.8.0-rc7) USB: EHCI: fix bug in scheduling periodic split transfers (appeared in 3.5.7.6/3.7.7/3.8.0-rc7) Hope someone can look into this bug soon! --- ApportVersion: 2.6.1-0ubuntu10 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: tysontan 2117 F.... pulseaudio /dev/snd/controlC1: tysontan 2117 F.... pulseaudio /dev/snd/pcmC1D0p: tysontan 2117 F...m pulseaudio CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found. DistroRelease: Ubuntu 12.10 HibernationDevice: RESUME=UUID=8545c3e2-caba-4eaa-8fa4-2fbebcc2d9bb InstallationDate: Installed on 2013-02-15 (14 days ago) InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.5) IwConfig: eth0 no wireless extensions. lo no wireless extensions. MachineType: LENOVO 0053A11 MarkForUpload: True Package: linux 3.5.0.26.32 PackageArchitecture: amd64 ProcEnviron: TERM=xterm PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.5.0-26-generic root=UUID=8c60a142-505f-4d74-afa0-37686558e86e ro quiet splash vt.handoff=7 ProcVersionSignature: Ubuntu 3.5.0-26.40-generic 3.5.7.6 RelatedPackageVersions: linux-restricted-modules-3.5.0-26-generic N/A linux-backports-modules-3.5.0-26-generic N/A linux-firmware 1.95 RfKill: Tags: quantal package-from-proposed running-unity third-party-packages Uname: Linux 3.5.0-26-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo dmi.bios.date: 10/11/2012 dmi.bios.vendor: LENOVO dmi.bios.version: 6QET70WW (1.40 ) dmi.board.name: 0053A11 dmi.board.vendor: LENOVO dmi.board.version: Not Available dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: Not Available dmi.modalias: dmi:bvnLENOVO:bvr6QET70WW(1.40):bd10/11/2012:svnLENOVO:pn0053A11:pvrThinkPadX201Tablet:rvnLENOVO:rn0053A11:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable: dmi.product.name: 0053A11 dmi.product.version: ThinkPad X201 Tablet dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1136110/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
