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alsa-project / alsa-lib

The Advanced Linux Sound Architecture (ALSA) - library
GNU Lesser General Public License v2.1
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Apple USB-C dongle cannot output 44100hz #322

Closed tw-hx closed 1 year ago

tw-hx commented 1 year ago

I have the same issue as outlined here, with an A2049 Apple USB-C to 3.5mm dongle: https://github.com/mikebrady/shairport-sync/issues/1504

Running Arch Linux with kernel 6.3.1-arch2-1, alsa-lib 1.2.9-1. Pipewire reports that the output is locked to 48000hz when it should be switching to 44100hz, and ALSA reports that this is the only detected supported rate:

$ cat /proc/asound/card0/stream0
Playback:
  Status: Running
    Interface = 1
    Altset = 1
    Packet Size = 288
    Momentary freq = 48000 Hz (0x30.0000)
  Interface 1
    Altset 1
    Format: S24_3LE
    Channels: 2
    Endpoint: 0x02 (2 OUT) (SYNC)
    Rates: 48000 - 48000 (continuous)
    Bits: 0
    Channel map: FL FR
  Interface 1
    Altset 2
    Format: S16_LE
    Channels: 2
    Endpoint: 0x02 (2 OUT) (SYNC)
    Rates: 48000 - 48000 (continuous)
    Bits: 0
    Channel map: FL FR

Thanks if this can be fixed. It seems like a regression between Linux 4.x and 5.x, and halfway through the above thread the user quantonian added the device to the ALSA quirks table and has posted a patch.

perexg commented 1 year ago

The quirk should be sent to the alsa-devel mailing list - https://www.alsa-project.org/wiki/Mailing-lists . This is tracker for the alsa library bugs.