[PROBLEM] Loopback function forcing 44.1kHz playback - Expected behavior or limitation?

[Tim Curtis]

CAVA prolly only supports 44.1K.

ALSA loopback in our build supports up to 384K.  Here's an example.

Code:

# Boss DAC (card2)
pi@moode9:~ $ cat /proc/asound/card2/pcm0p/sub0/hw_params
access: MMAP_INTERLEAVED
format: S16_LE
subformat: STD
channels: 2
rate: 384000 (768000/2)
period_size: 32768
buffer_size: 131072

# Loopback (card3)
pi@moode9:~ $ cat /proc/asound/card3/pcm0p/sub0/hw_params
access: MMAP_INTERLEAVED
format: S16_LE
subformat: STD
channels: 2
rate: 384000 (384000/1)
period_size: 32768
buffer_size: 131072

pi@moode9:~ $ aplay -l
[size=small][font=Monaco, Consolas, Courier, monospace]**** List of PLAYBACK Hardware Devices ****[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]card 0: vc4hdmi0 [vc4-hdmi-0], device 0: MAI PCM i2s-hifi-0 [MAI PCM i2s-hifi-0][/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevices: 1/1[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevice #0: subdevice #0[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]card 1: vc4hdmi1 [vc4-hdmi-1], device 0: MAI PCM i2s-hifi-0 [MAI PCM i2s-hifi-0][/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevices: 1/1[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevice #0: subdevice #0[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]card 2: BossDAC [BossDAC], device 0: Boss DAC HiFi [Master] pcm512x-hifi-0 [Boss DAC HiFi [Master] pcm512x-hifi-0][/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevices: 0/1[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevice #0: subdevice #0[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]card 3: Loopback [Loopback], device 0: Loopback PCM [Loopback PCM][/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevices: 7/8[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevice #0: subdevice #0[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevice #1: subdevice #1[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevice #2: subdevice #2[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevice #3: subdevice #3[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevice #4: subdevice #4[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevice #5: subdevice #5[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevice #6: subdevice #6[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevice #7: subdevice #7[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]card 3: Loopback [Loopback], device 1: Loopback PCM [Loopback PCM][/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevices: 8/8[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevice #0: subdevice #0[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevice #1: subdevice #1[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevice #2: subdevice #2[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevice #3: subdevice #3[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevice #4: subdevice #4[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevice #5: subdevice #5[/font][/size]
[size=small][font=Monaco, Consolas, Courier, monospace]  Subdevice #6: subdevice #6[/font][/size]
 Subdevice #7: subdevice #7