Re: Re^2: /dev/* and ALSA.

[Ralf Mardorf <ralf.mardorf@alice-dsl.net>]

On Tue, 2014-02-04 at 11:08 -0800, peter@easthope.ca wrote:
> *	From: Ralf Mardorf 
> *	Date: Mon, 03 Feb 2014 21:12:22 +0100
> > [rocketmouse@archlinux ~]$ hdspmixer
> > Card 0: ...
> > ...
> 
> peter@dalton:~$ cat /proc/asound/cards
>  0 [SI7012         ]: ICH - SiS SI7012
>                       SiS SI7012 with ALC655 at irq 18
>  1 [NX6000         ]: USB-Audio - MicrosoftB. LifeCam NX-6000
>                       Microsoft MicrosoftB. LifeCam NX-6000 at usb-0000:00:03.3-
> 8, high speed
>  2 [Set            ]: USB-Audio - C-Media USB Headphone Set
>                       C-Media USB Headphone Set at usb-0000:00:08.0-3, full spee
> d
>  3 [Device         ]: USB-Audio - C-Media USB Audio Device
>                       C-Media USB Audio Device at usb-0000:00:03.2-1, full speed
> 
> If card numbers are assigned randomly and the VoIP sends the ring to 
> card 0, then after approximately 25% of reboots, the ring will go to 
> the speakers on USB Audio.  After about 75% of reboots the ring will 
> go to an inaudible device.  
> 
> > IOW you need to use
> > 
> > options snd slots=snd_usb_audio
> 
> That will restrict possible output devices to two. 
> After approximately 50% of reboots the ring will go to 
> the speakers.  Otherwise the ring will go to the headset
> which I only wear a fraction of any day.

You could test the following. Connect the two USB devices to USP ports
that have different IRQs and then use

options snd slots=snd_usb_audio,snd_usb_audio

I use two identical PCI cards, both have the same name, but they have
different IRQs. The hw order for each reboot is the same.

[rocketmouse@archlinux ~]$ sudo modprobe snd_ice1712
[rocketmouse@archlinux ~]$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: HDSPMx579bcc [RME AIO_579bcc], device 0: RME AIO [RME AIO]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: EWX2496 [TerraTec EWX24/96], device 0: ICE1712 multi [ICE1712 multi]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: EWX2496_1 [TerraTec EWX24/96], device 0: ICE1712 multi [ICE1712 multi]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
[rocketmouse@archlinux ~]$ hdspmixer 
Card 0: RME AIO S/N 0x579bcc at 0xfddf0000, irq 18
Card 1: TerraTec EWX24/96 at 0xbf00, irq 20
Card 2: TerraTec EWX24/96 at 0xbb00, irq 21
Card 3: USB Device 0x170b:0x11 at usb-0000:00:13.0-2, full speed
[rocketmouse@archlinux ~]$ cat /etc/modprobe.d/alsa-base.conf
# ALSA module ordering
options snd slots=snd_hdspm,snd_ice1712,snd_ice1712
                            ^^^^^^^^^^^ ^^^^^^^^^^^