On a different machine (no Nvidia) but with the same monitor, I can also reproduce this over DisplayPort but not over HDMI.
So I don't think that the Nvidia graphics card/driver is to blame. Instead, it seems like there's a general DisplayPort-related issue either in Linux/Alsa or in my cable/monitor (but if so, then Windows has a workaround for that issue, which could hopefully be implemented in Linux/Alsa too). Either way, it seems like this is something for the Alsa team to debug, and I'm happy to provide more information or run more experiments/tests. -- 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/1924846 Title: [550-254ng, Nvidia GPU 60 HDMI/DP, Digital Out, DisplayPort] Crackling sound during quiet parts of video, with DisplayPort only Status in alsa-driver package in Ubuntu: New Bug description: When I play YouTube videos, then in the quiet parts of the video (i.e. in pauses between sentences, even if they are very brief), I hear a popping/crackling sound on my headphones connected through my DisplayPort monitor and my Nvidia GeForce GTX 745 card (I have this PC: https://www.notebooksbilliger.de/hp+pavilion+550+254ng+intel+core+i5+6400 and an Asus PB248Q monitor). Depending on the video and how many pauses the speakers make, this is very annoying. I've run a long series of experiments, see https://forums.linuxmint.com/viewtopic.php?f=48&t=347176 for details. In summary, I can reproduce this: - With any installed Linux OSes (Ubuntu or Mint) or with live sticks (tried Ubuntu, Mint, PopOS and Manjaro). - With the open-source driver (Nouveau) or with various versions of the Nvidia driver. - With Chrome or Firefox or even an Audacity recording (from the DisplayPort output's audio monitor in PulseAudio) of the same audio stream. - Even when I try the usual fixes like tsched=0, disabling module-suspend-on-idle, disabling /sys/module/snd_hda_intel/parameters/power_save or position_fix=1 or =2. - Even when I don't use PulseAudio, but use `apulse ffplay ...` to play a file directly to ALSA. - NOT on Windows. Any browser and any video/sound file works fine on Windows with exactly the same hardware. - NOT with HDMI. The same card/monitor/headphones connected over HDMI (aka. "HDMI / DisplayPort 3" aka. "hdmi-stereo-extra2" aka. device number 8 aka. "HDMI 2") works fine. Only over DisplayPort (aka. "HDMI / DisplayPort 4" aka. "hdmi-stereo-extra3" aka. device number 9 aka. "HDMI 3") it crackles. - NOT when I save the problematic Audacity recording as a wav/mp3 file (and play it in any media player or with `apulse aplay ...`) or when I convert it to 16-Bit PCM in Audacity (and back to 32-bit float). My suspicion is that this somehow gets rid of the pauses / quiet parts by writing sth like zeros in there. - NOT when I have some other continuous audio running at the same time, e.g. if I turn on some radio in Rhythmbox and play the problematic video at the same time, there's no crackles. Again my suspicion is that this gets rid of the quiet parts -- not in the video, but in the mixed stream sent to the audio device. This bug report is produced from `ubuntu-bug audio` on a freshly created Ubuntu LTS live USB stick with all default values, where I've just reconfirmed that DisplayPort is broken and HDMI works. Thanks for your help! ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: alsa-base 1.0.25+dfsg-0ubuntu5 ProcVersionSignature: Ubuntu 5.8.0-43.49~20.04.1-generic 5.8.18 Uname: Linux 5.8.0-43-generic x86_64 NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair ApportVersion: 2.20.11-0ubuntu27.16 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: ubuntu 5070 F.... pulseaudio /dev/snd/pcmC0D0c: ubuntu 5070 F...m pulseaudio /dev/snd/controlC1: ubuntu 5070 F.... pulseaudio CasperMD5CheckResult: pass CasperVersion: 1.445.1 CurrentDesktop: ubuntu:GNOME Date: Sat Apr 17 11:25:05 2021 LiveMediaBuild: Ubuntu 20.04.2.0 LTS "Focal Fossa" - Release amd64 (20210209.1) PackageArchitecture: all ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=C.UTF-8 SHELL=/bin/bash SourcePackage: alsa-driver Symptom: audio Symptom_AlsaPlaybackTest: ALSA playback test through plughw:NVidia successful Symptom_Card: GM107 High Definition Audio Controller [GeForce 940MX] - HDA NVidia Symptom_Jack: Digital Out, HDMI Symptom_PulsePlaybackTest: PulseAudio playback test successful Symptom_Type: Underruns, dropouts, or "crackling" sound Title: [550-254ng, Nvidia GPU 60 HDMI/DP, Digital Out, HDMI] Underruns, dropouts or crackling sound UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 01/18/2018 dmi.bios.release: 5.11 dmi.bios.vendor: AMI dmi.bios.version: A0.20 dmi.board.asset.tag: CZC6057CYQ dmi.board.name: 2B47 dmi.board.vendor: HP dmi.board.version: 1.04 dmi.chassis.asset.tag: CZC6057CYQ dmi.chassis.type: 3 dmi.chassis.vendor: HP dmi.modalias: dmi:bvnAMI:bvrA0.20:bd01/18/2018:br5.11:svnHP:pn550-254ng:pvr1.04:rvnHP:rn2B47:rvr1.04:cvnHP:ct3:cvr: dmi.product.family: 103C_53316J G=D dmi.product.name: 550-254ng dmi.product.sku: V2F29EA#ABD dmi.product.version: 1.04 dmi.sys.vendor: HP To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1924846/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
