Well, it's still not clear who to blame.  Practically seen, the problem
appears on a certain Realtek codecs just because there are such codec
chips on the market for major mobos.  Except for a few vendors (like
Apple), all boards are equipped with Realtek codecs.  So, I still
suspect the problem being in HD-audio controller -- the AMD chipset
side.

Can people check whether any of workarounds have any effect?  For
example,

- Make sure the existing quirks for ATI boards:
  Check the PCI device ID of your HD-audio controller connected to the onboard 
analog audio.  You may have multiple HD-audio controller entries, and one of 
them is for HDMI and another for the onboard audio.
  The table in sound/pci/hda/hda_intel.c indicates the type and the quirk.  The 
AMD one should be with AZX_DCAPS_PRESET_ATI_SB.

- Disable the page caching.
  This can be done by passing snoop=0 option.  But maybe it's more interesting 
to forcibly disable the cache while keeping the PCI snoop enabled, e.g. apply a 
patch like:

--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -1681,6 +1681,7 @@ static int azx_create(struct snd_card *card, struct 
pci_dev *pci,
                chip->single_cmd = single_cmd;
 
        azx_check_snoop_available(chip);
+       chip->uc_buffer = true; // XXX
 
        if (bdl_pos_adj[dev] < 0)


- Adjust more quirk bits:
  AZX_DCAPS_PRESET_ATI_SB contains AZX_DCAPS_NO_TCSL.  Try to remove this flag, 
for example.
  Also, add more flags, e.g. AZX_DCAPS_NO_MSI, AZX_DCAPS_NO_MSI64, 
AZX_DCAPS_NO_64BIT, AZX_DCAPS_4K-BDLE_BOUNDARY.

- Try different sample rates, format, period and buffer sizes:
  At best test with aplay / arecord with -Dhw option to skip pulseaudio.
  (You can run it over pasuspender.)
  Check various parameters, e.g. 44.1k vs 48kHz, S16_LE vs S32_LE.  Try to 
align the period size and the buffer size to be 4kB.

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You received this bug notification because you are a member of Desktop
Packages, which is subscribed to pulseaudio in Ubuntu.
https://bugs.launchpad.net/bugs/1801540

Title:
  Microphone distorted sound on ALC892/1220 on AMD chipsets

Status in Linux:
  Confirmed
Status in linux package in Ubuntu:
  Won't Fix
Status in pulseaudio package in Ubuntu:
  Won't Fix

Bug description:
  Not sure if I'll report this upstream but there is definitely an issue
  with microphone recording on my desktop, this is not happening on my
  laptop which has a different codec.

  Already tried all workarounds possible, no luck. Only with my desktop
  with this particular motherboard. No issues in Windows, the sound
  recorded in there is distorted and has some static and robotic tone on
  high-pitch.

  alsa-info on the attachments

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