Hey guys, I was the one who started the amd chipset rumor. We've been talking about the issue over at https://forum.level1techs.com/t/rodecaster-pro-bad-audio-out-solved- ish/170601.
At first I thought it was an amd vs intel issue just due to the hardware I had on hand that worked/didn't work. After someone popped in mentioning their intel device having the issue and a pcie card they bought also having the issue it seems like the issue is with all usb3.2 gen2x2 host controllers, or at least that's my best guess. I picked up a different pcie usb card than the person had trouble with and that was 3.2 gen2x2 capable. I can reproduce the issue on both it, and my motherboard usb ports. However, using a usb3.0 pcie card the issue goes away. One strange thing to me about all of this is that the rodecaster pro is negotiating usb2 480mbps connections, so i'm not sure why a later usb spec would mess with that. It's also worth noting that the issue seems to be related to the usb host controller itself as using ports capable of different speeds/going through usb hubs or directly connecting doesn't change the behavior. I also don't have a usb 3.1 gen2 host controller to test to see if the issue is truly only with usb 3.2 gen2x2 controllers. Debugging any further than that is proving difficult though. I did a diff on both my lsusb and pw-dump output and the only changes in the two were paths/ids which are expected to change. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to alsa-driver in Ubuntu. https://bugs.launchpad.net/bugs/1927255 Title: [USB-Audio - RODECaster Pro, playback] Sound is distorted (20.04) Status in alsa-driver package in Ubuntu: Confirmed Bug description: I got a Rodecaster Pro USB device that has been causing trouble before and already lead to quirk handling in the kernel for the sample rate, see https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/sound/usb/format.c?h=v5.8#n412 The Rodecaster is running fine on my laptop, but on my desktop, only audio input is working. The audio output is distorted. It's played kind of very slowly. Interestingly, if the source is a video file, the video plays slower, e.g. YouTube in a browser. I have never seen anything like that before. I have tried to figure out what the cause might be and I think I have reached the end of where I can get to on my own. I have documented most things at https://ubuntuforums.org/showthread.php?t=2461568 Putting my last step it in a nutshell: I have booted both my computers with a plain Ubuntu 21.04 from a pen drive (it uses kernel version 5.11.0-16-generic) to make sure it's not some different configuration that I have set up over the years on my systems (both Ubuntu 20.04 with kernel 5.8.18). I attached the Rodecaster. It runs fine on my laptop, but not on my desktop (used the output test from). I then detected the card number with aplay -l I killed pulseaudio with pulseaudio -k I then played the same sample (encoded in 48000 Hz in PCM signed 32 bit little endian format) using aplay -f S32_LE -c 2 -r 48000 -D hw:x ~/sample.wav where x is the appropriate card number and the rest of the arguments meet the Rodecaster's narrow specification. It's playing fine on the laptop, but distorted on the desktop. As far as I understand using aplay this way without a plugin should send the file directly to the device, so I assume there's something on the way from aplay to the Rodecaster that's interfering (kernel or even some piece of hardware) - and that definitely is where my expertise ends (rather a little before :-)). I'll gladly contribute any information that could be useful and I will willingly help to debug this problem if it may be related to the kernel. If there's anything I can do, please let me know. Cheers, Oliver ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: alsa-base 1.0.25+dfsg-0ubuntu5 Uname: Linux 5.8.18-050818-generic x86_64 NonfreeKernelModules: blackmagic_io nvidia_modeset nvidia ApportVersion: 2.20.11-0ubuntu27.16 Architecture: amd64 CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME CurrentDmesg: Error: command ['dmesg'] failed with exit code 1: dmesg: read kernel buffer failed: Operation not permitted Date: Wed May 5 18:28:46 2021 InstallationDate: Installed on 2020-05-15 (355 days ago) InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423) PackageArchitecture: all SourcePackage: alsa-driver Symptom: audio Symptom_AlsaPlaybackTest: ALSA playback test through plughw:Pro failed Symptom_Card: RODECaster Pro - RODECaster Pro Symptom_Type: Digital clip or distortion, or "overdriven" sound Title: [USB-Audio - RODECaster Pro, playback] Sound is distorted UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 10/30/2020 dmi.bios.release: 5.17 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: A.40 dmi.board.asset.tag: To be filled by O.E.M. dmi.board.name: B550-A PRO (MS-7C56) dmi.board.vendor: Micro-Star International Co., Ltd. dmi.board.version: 1.0 dmi.chassis.asset.tag: To be filled by O.E.M. dmi.chassis.type: 3 dmi.chassis.vendor: Micro-Star International Co., Ltd. dmi.chassis.version: 1.0 dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrA.40:bd10/30/2020:br5.17:svnMicro-StarInternationalCo.,Ltd.:pnMS-7C56:pvr1.0:rvnMicro-StarInternationalCo.,Ltd.:rnB550-APRO(MS-7C56):rvr1.0:cvnMicro-StarInternationalCo.,Ltd.:ct3:cvr1.0: dmi.product.family: To be filled by O.E.M. dmi.product.name: MS-7C56 dmi.product.sku: To be filled by O.E.M. dmi.product.version: 1.0 dmi.sys.vendor: Micro-Star International Co., Ltd. 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