USB Webcam Grabs ALSA Card Index 0
Hi,
I have two usb devices on my system, which register with the snd_usb_audio
module, a USB Headset and a USB webcam (has a microphone built-in). I use
options snd-usb-audio index=-2
in modprobe.d to keep the usb devices away from card index 0, since I want to
be snd_hda_intel the default.
That works well as long as I do not plug in the USB webcam. If I plug in the
USB webcam, the webcam grabs card index 0.
Does anybody understand why that is?
Here are some more detailed data (the usb device asr both from Logitech):
blackbox:~# lsusb
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 006: ID 046d:0825 Logitech, Inc. Webcam C270
Bus 001 Device 005: ID 046d:0a44 Logitech, Inc.
Bus 001 Device 004: ID 04b4:6560 Cypress Semiconductor Corp. CY7C65640 USB-2.0
"TetraHub"
Bus 001 Device 003: ID 0781:5567 SanDisk Corp. Cruzer Blade
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 002: ID 046d:c05b Logitech, Inc. M-U0004 810-001317 [B110
Optical USB Mouse]
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
blackbox:~# cat /proc/asound/cards
0 [U0x46d0x825 ]: USB-Audio - USB Device 0x46d:0x825
USB Device 0x46d:0x825 at usb-0000:00:1a.7-5.4, high
speed
1 [Headset ]: USB-Audio - Logitech USB Headset
Logitech Logitech USB Headset at usb-0000:00:1a.7-5.1,
full speed
2 [Intel ]: HDA-Intel - HDA Intel
HDA Intel at 0xfe7f4000 irq 45
blackbox:~# cat /proc/asound/modules
0 snd_usb_audio
1 snd_usb_audio
2 snd_hda_intel
blackbox:~# cat /etc/modprobe.d/alsa-base.conf
# autoloader aliases
install sound-slot-0 /sbin/modprobe snd-card-0
install sound-slot-1 /sbin/modprobe snd-card-1
install sound-slot-2 /sbin/modprobe snd-card-2
install sound-slot-3 /sbin/modprobe snd-card-3
install sound-slot-4 /sbin/modprobe snd-card-4
install sound-slot-5 /sbin/modprobe snd-card-5
install sound-slot-6 /sbin/modprobe snd-card-6
install sound-slot-7 /sbin/modprobe snd-card-7
# Cause optional modules to be loaded above generic modules
install snd /sbin/modprobe --ignore-install snd && { /sbin/modprobe --quiet
snd-ioctl32 ; /sbin/modprobe --quiet snd-seq ; : ; }
install snd-rawmidi /sbin/modprobe --ignore-install snd-rawmidi && {
/sbin/modprobe --quiet snd-seq-midi ; : ; }
install snd-emu10k1 /sbin/modprobe --ignore-install snd-emu10k1 && {
/sbin/modprobe --quiet snd-emu10k1-synth ; : ; }
# Keep snd-pcsp from beeing loaded as first soundcard
options snd-pcsp index=-2
# Keep snd-usb-audio from beeing loaded as first soundcard
options snd-usb-audio index=-2
# Prevent abnormal drivers from grabbing index 0
options bt87x index=-2
options cx88_alsa index=-2
options snd-atiixp-modem index=-2
options snd-intel8x0m index=-2
options snd-via82xx-modem index=-2
blackbox:~#
Many thanks,
Rainer
--
Rainer Dorsch
http://bokomoko.de/
Reply to: