Re: Interesting problem with hotplug and Midisport 2x2 on Mdk 9.0

[Takashi Iwai <tiwai@suse.de>]

At Thu, 27 Feb 2003 13:00:10 -0500,
Ivica Bukvic wrote:
> 
> Hi all,
> 
> This is my latest finding. Thanks to the script I got from Jaroslav, I
> am now able to hotplug my midisport 2x2 whenever I wish to do so.
> However, there is an interesting problem surrounding Mdk9.0.
> 
> If I use the planet ccrma's hotplug ver. 2002_8_26 (by forcing upgrade
> of the mdk's), I get the fxload and all the goodies making the midisport
> work right out-of-the-box. However, with one huge flaw: 
> 
> When I unplug the midisport (after having the alsasound hotplug script
> installed), my kernel oops and system freezes telling me something about
> "disabling interrupt handler." (if someone tells me where I can track
> this information log I will be happy to forward it). So, I am simply not
> allowed to unplug the device.
> 
> In addition my /var/log/messages relatively often spits out the
> following message:
> <date> <host> kernel: usb-uhci.c: interrupt, status 3, frame#
> <some_number>
> 
> I've tracked down the problem to the /sbin/modprobe -r snd-usb-midi (and
> snd-usb-audio). If I move this thing somewhere else in the alsasound
> hotplug script (like purging it at load-time and then reloading the
> driver, rather than on disconnect) then the freeze occurs at that point.
> When I comment it out, no freezes occur. So, I am pretty sure that is
> the culprit.

hmm, the hot unplugging of ALSA usb devices was improved in the recent
version - basically i didn't see problems with the devices i have.
but i've not tested with midi devices, so this might be a problem.

just make sure that you unload snd-usb-audio (snd-usb-midi doesn't
exist any longer) before unplugging the device.


Takashi


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