Jaroslav Kysela wrote:
> On Tue, 11 Nov 2008, Takashi Iwai wrote:
>
>>> Almost all devices can be managed with udev rules, that is where the
>>> system is designed for, there are also alsa rules in there, if they
>>> don't work what is wrong then? is it an alsa issue, or udev, what are
>>> the dependencies when alsa uses hardware. How are the /dev/snd/* devices
>>> used and what is the /proc/asound/* for ?
>> The card index mechanism in ALSA was introduced much before udev
>> was born. It's just a legacy mechanism, but it's hard to kill without
>> breaking the running system, unfortunately.
>
> Note that you can identify your card via the text identification (check
> /proc/asound/cards to get it in []). You can set this identification in
> the module insert time and use for example 'hw:Intel' in your apps without
> bothering with indexes.
>
> The missing part is the modification of this text identification using
> sysfs at runtime for udev. Some time ago, I was trying to add this setup
> to /sys/class/sound, but the sysfs core code was not prepared for this
> change. I'll try to check the situation again.
>
> Jaroslav
I wish it was as simple as using the [identification ]. The [id..] is
not reliable for one usb port, as you can below I just unplugged some
usb audio devices and plugged it in again. The [id] does not match the
same usb location port anymore, so breaking the
user->unique-usb-port-audio-device connection.
Being able to set the id with udev would be an possible solution.
cat /proc/asound/cards (first)
0 [Intel ]: HDA-Intel - HDA Intel
HDA Intel at 0xf7db8000 irq 16
1 [pcsp ]: PC-Speaker - pcsp
Internal PC-Speaker at port 0x61
2 [Em28xx Audio ]: Empia Em28xx AudEm28xx Audio - Em28xx Audio
Empia Em28xx Audio
3 [default ]: USB-Audio - USB AUDIO
USB AUDIO at usb-0000:00:1d.7-4.1, full speed
4 [default_1 ]: USB-Audio - USB AUDIO
USB AUDIO at usb-0000:00:1d.7-4.2, full speed
5 [default_2 ]: USB-Audio - USB AUDIO
USB AUDIO at usb-0000:00:1d.7-4.3, full speed
6 [default_3 ]: USB-Audio - USB AUDIO
USB AUDIO at usb-0000:00:1d.7-4.4, full speed
cat /proc/asound/cards (second)
0 [Intel ]: HDA-Intel - HDA Intel
HDA Intel at 0xf7db8000 irq 16
1 [pcsp ]: PC-Speaker - pcsp
Internal PC-Speaker at port 0x61
3 [default ]: USB-Audio - USB AUDIO
USB AUDIO at usb-0000:00:1d.7-4.3, full speed
4 [default_1 ]: USB-Audio - USB AUDIO
USB AUDIO at usb-0000:00:1d.7-4.2, full speed
5 [default_2 ]: USB-Audio - USB AUDIO
USB AUDIO at usb-0000:00:1d.7-4.4, full speed
6 [default_3 ]: USB-Audio - USB AUDIO
USB AUDIO at usb-0000:00:1d.7-4.1, full speed
Also the limitation of [0-7] devices is kind of unclear does it
something to do with limitations of timers?
Best regards,
Jelle
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