Fwd: Apple USB-C 3.5mm dongle cannot output 41000hz

[Bagas Sanjaya]

Hi,

I notice a regression report on Bugzilla [1]. Quoting from it:

> Overview:
> With an A2049 Apple USB-C to 3.5mm DAC dongle, I have the same issue as outlined in this link: ALSA won't detect 44100Hz as an available sample rate:
> https://github.com/mikebrady/shairport-sync/issues/1504
> 
> 
> Steps to Reproduce:
> Play a 44.1Khz audio file.
> 
> 
> Actual Results:
> Pipewire reports that the output is locked to 48000hz, 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
> 
> 
> Expected Result:
> It should be switching between 44100-48000hz, the only two rates it supports.
> 
> 
> Build Date and Hardware:
> Running Arch Linux with kernel 6.3.4-arch1-1, alsa-lib 1.2.9-1.
> AMD Ryzen 3600 on a MSI B450M Mortar Max motherboard
> 
> 
> Additional Information:
> 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:
> 
> https://github.com/mikebrady/shairport-sync/issues/1504#issuecomment-1193355701
> 
> Thanks if this can be fixed in the kernel. The dongle in question is US $9:
> https://www.apple.com/shop/product/MU7E2AM/A/usb-c-to-35-mm-headphone-jack-adapter

See bugzilla for the full thread.

Unfortunately, the reporter said that he can only run kernel as
old as 5.6, as older than that, he experiences unrelated GPU crashes,
so he can't bisect this regression.

Anyway, I'm adding it to regzbot:

#regzbot introduced: v4.19..v5.10 https://bugzilla.kernel.org/show_bug.cgi?id=217501
#regzbot title: 44100hz is mistaken as 48000hz on Apple Headphone Jack Adapter
#regzbot link: https://github.com/mikebrady/shairport-sync/issues/1504
#regzbot link: https://www.audiosciencereview.com/forum/index.php?threads/review-apple-vs-google-usb-c-headphone-adapters.5541/page-32

Thanks.

[1]: https://bugzilla.kernel.org/show_bug.cgi?id=217501

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