Re: [linux-audio-user] Hot(un)plug

New Message Reply About this list Date view Thread view Subject view Author view Other groups

Subject: Re: [linux-audio-user] Hot(un)plug
From: Frank Pirrone (fpirrone_AT_localnet.com)
Date: Thu Feb 27 2003 - 04:08:20 EET


Frank Barknecht wrote:

>Hallo,
>Tim Hall hat gesagt: // Tim Hall wrote:
>
>
>
>>hotplug is also involved in a chain of dependencies, which go:
>>hotplug <-ezusbmidi<-demudi-midi<-demudi-soundapps.
>>I'm hoping the last two are 'empty' packages, but I'm wary, because the ONE
>>thing I DO want (and what got me into this mess in the first place) is to be
>>able to fire up an external synth.
>>firewire, usb & pcmcia I can do without.
>>I'm being double cautious due to the number of times I've lost the function I
>>needed due to deleting something that seemed irrelevant.
>>
>>
>
>Be a little but careful here. demudi-midi and demudi-soundapps are so
>called tasks, IIR, they are itself empty, but depend on other
>packages to fulfill a task like "midi software in general". So I think
>it might be okay to remove them (try "apt-get -s remove hotplug"
>first), but YMMV.
>
>I don't quite see why you *want* to remove hotplug. I see a lot of
>harmless warning messages on startup. That's perfectly normal on
>Linux.
>
>ciao
>
>
Just a comment on hotplug: I was receiving an error when ALSA started
up indicating that the driver was already running, and there indeed were
some modules loaded, but not the snd-cs4236 and its support modules. I
had to do "service alsasound restart" to get the sound card/chip running.

What was happening was the modules.conf statement "alias usb-controller
uhci" was causing my Midisport 2x2 to initialize, and have its firmware
downloaded by ezusbmidi. Without this line, the box lay dormant, but
with it some ALSA modules were loading prematurely.

So, here's the point and the solution: The file /etc/hotplug/blacklist
is to allow hotplug to recognize and even initialize USB (and other
busses) devices without loading the blacklisted modules yet. These
modules will be loaded later in the boot process (when alsasound
executes for example) that will do the job at the proper time.

In my case listing the modules that loaded when Midisport 2x2 fired up,
held them in check until alsasound was ready to load the entire suite of
sound support modules for all devices.

Moral of the story: Hotplug is valuable and powerful (I can
disconnect/reconnect my UBS midi interface, scanner, and minidisk
interface as seamlessly as Windoze) and its behavior can be easily
controlled by the scripts and config files in /etc/hotplug.

Frank


New Message Reply About this list Date view Thread view Subject view Author view Other groups

This archive was generated by hypermail 2b28 : Thu Feb 27 2003 - 04:03:59 EET