Re: [LAU] New User

Mark Knecht wrote:
> On Wed, Mar 19, 2008 at 1:52 PM, Cesare Marilungo
> <cesare@email-addr-hidden> wrote:
>
>> >
>> Hi Mark,
>> what if you want to control the order of two different devices both usb
>> (and so both handled by the snd-usb-audio module? In particular I have
>> an usb audio interface and usb keyboard which is recognized as an audio
>> device (even if it doesn't have audio functionalities). The order
>> switches randomly at each reboot.
>>
>> Thanks in advance,
>>
>> -c.
>>
>>
>
> Hi Cesare,
> Good to hear from you.
>
> This was the subject of another thread I asked on (I think) this
> list a week or two ago. Apparently there is no way to do this for
> cards using identical drivers. I had an opportunity to put together a
> machine using 3 HDSP9652's but I needed to know that order of the
> cards and ensure that every time I booted that the order wouldn't
> change. The response I got was that Alsa cannot handle this.
>
Yes, I remember that thread. But I thought my case would be addressable
since the device are, at least, different. I also thought it should be
quite common to have both an usb audio interface and an usb midi keyboard.
> I did a little bit of study of how Windows does this for internal
> cards. It appears that Windows pays attention to the resources the
> device is using and keeps track of those. PCI bus and slot number. IRQ
> assingment, etc. As loog as things don't change then it will comtinue
> to use them the same way every day.
>
> For external devices it seems that the best way to do this in Linux
> is though udev. Most external devices have a UUID of some type. If you
> can identify the UUID and then build a udev rule it should work but
> that's all way beyond my skill set.
>
I'll try this. Thanks.
> Hope this helps,
> Mark
>
>
>
All the best,

-c.
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Received on Thu Mar 20 00:15:07 2008