Re: virmidi, hotplug and udev

[Takashi Iwai <tiwai@suse.de>]

At Sun, 28 Nov 2004 18:51:29 -0300,
Carlos Pita wrote:
> 
> Hi!
> 
> I'm using kernel 2.6.8 with hotplug enabled and udev
> (distro: debian sarge).
> 
> I need to use the snd-virmidi to create a virtual sound card
> with its raw midi devices.
> 
> I do:
>   modprobe snd-virmidi
> 
> Does this generate a hotplug event? Or at least an udev event?
> 
> I ask it because here the order is somewhat inverted. Normally
> a device is cold/hot plugged and modprobe is run in
> response to a subsequent hotplug event. But here the device is
> added as the effect of a previous modprobe. One thing I see
> is that modprobe would be retried as part of the event processing,
> that's innocuous but ugly.
> 
> Finally, do you know how to write the udev rules to generate
> the OSS raw midi devices. Currently, the only rules related
> to ALSA in my /etc/udev/rules.d/udev.rules are:
> 
> # ALSA devices
> KERNEL="controlC[0-9]*", NAME="snd/%k"
> KERNEL="hw[CD0-9]*",    NAME="snd/%k"
> KERNEL="pcm[CD0-9cp]*", NAME="snd/%k"
> KERNEL="midi[CD0-9]*",  NAME="snd/%k"
> KERNEL="timer",         NAME="snd/%k"
> KERNEL="seq",           NAME="snd/%k"
> 
> Most of the OSS devices are generated at boot time by
> udevstart. But /dev/midi10.../dev/midi13 are missing after
> modprobing snd-virmidi.

There are no /dev/midi1x devices on OSS.
As written in my last post, the OSS device has no concept of "card".
It just accepts the device in a serial order.

Nevertheless, OSS supports only up to 4 devices for /dev/midi0?.
(You can use more 4 devices with /dev/amidi?, too, though.)


Takashi


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