snd_bt87x on Kworld KW-TV878RF

[Tamás Hámor]

Hi,

After reinstalling Linux (Xubuntu 20.04.1) on my old computer the sound
stopped working on my Kworld KW-TV878RF tuner card. I load the bttv module
with options "card=78 radio=1" and snd-bt87x with "load_all". The
corresponding dmesg is below:

[   15.626992] bttv: driver version 0.9.19 loaded
[   15.626994] bttv: using 8 buffers with 2080k (520 pages) each for capture
[   15.627024] bttv: Bt8xx card found (0)
[   15.627166] bttv: 0: Bt878 (rev 17) at 0000:04:01.0, irq: 18, latency:
32, mmio: 0xf0001000
[   15.627177] bttv: 0: using: Jetway TV/Capture JW-TV878-FBK, Kworld
KW-TV878RF [card=78,insmod option]
[   15.627359] bttv: 0: tuner type=5
[   15.908280] bttv: 0: audio absent, no audio device found!
[   16.454464] bttv: 0: Setting PLL: 28636363 => 35468950 (needs up to
100ms)
[   16.496037] bttv: PLL set ok
[   16.497200] bttv: 0: registered device video0
[   16.497273] bttv: 0: registered device vbi0
[   16.497357] bttv: 0: registered device radio
...
[  682.784918] snd_bt87x 0000:04:01.1: unknown card 0x878-0x00:0x00
[  682.784919] snd_bt87x 0000:04:01.1: please mail id, board name, and, if
it works, the correct digital_rate option to <alsa-devel at alsa-project.org>
[  682.785084] snd_bt87x 0000:04:01.1: bt87x0: Using board 0, analog,
digital (rate 32000 Hz)

The lspci output is:
04:01.0 Multimedia video controller: Brooktree Corporation Bt878 Video
Capture (rev 11)
Flags: bus master, medium devsel, latency 32, IRQ 18
Memory at f0001000 (32-bit, prefetchable) [size=4K]
Capabilities: [44] Vital Product Data
Capabilities: [4c] Power Management version 2
Kernel driver in use: bttv
Kernel modules: bttv

04:01.1 Multimedia controller: Brooktree Corporation Bt878 Audio Capture
(rev 11)
Flags: bus master, medium devsel, latency 32, IRQ 18
Memory at f0000000 (32-bit, prefetchable) [size=4K]
Capabilities: [44] Vital Product Data
Capabilities: [4c] Power Management version 2
Kernel driver in use: snd_bt87x

uname -a
Linux ubuntu 5.4.0-52-generic #57-Ubuntu SMP Thu Oct 15 10:57:00 UTC 2020
x86_64 x86_64 x86_64 GNU/Linux

Regards,

Tamas