Re: USB Webcam Grabs ALSA Card Index 0
* Rainer Dorsch <ml@bokomoko.de> [2014-04-06 11:00 +0200]:
> 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.
Sounds somewhat different than in your bugreport.
> 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
Create as root a file /etc/modprobe.d/alsa_local.conf:
###
options snd slots=snd-hda-intel
options snd-usb-audio index=1,2 vid=0x46d,0x46d pid=0xa44,0x825
###
This should preserve the first soundslot for your intel card. Your
headset (ID 046d:0a44) will become index 1 and your webcam (ID
046d:0825) index 2 though.
See http://alsa.opensrc.org/MultipleCards
Elimar
--
The path to source is always uphill!
-unknown-
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