Re: [linux-usb-devel] 2.6.0-test4 - PL2303 OOPS - see also 2.4.22: OOPS on disconnect PL2303 adapter

[Michael Frank <mhf@linuxmail.org>]

On Wednesday 03 September 2003 00:43, Greg KH wrote:
> On Tue, Sep 02, 2003 at 01:39:08AM +0800, Michael Frank wrote:
> > PL2303 is used to connect the serial console on a classic serial port
> > of a test machine. HW nandshaking is used
> > The test machine reboots once a minute and dumps lots of messages
> >
> > Frequently:
> > - driver hangs
> > - userspace (cu) can't be stopped
> > - pl2303 and/or usbserial can't be unloaded
> > - USB interrupts stop
> > - problems result in requiring a reboot.
>
> Hm, it looks like you physically removed the device, is that correct?
> Or were you just unloading the pl2303 and other USB drivers and then
> reloading them?
>
> What exactly were you doing in this log?
>
> Oh, and can you send a copy of /proc/bus/usb/devices with your pl2303
> device plugged in?
>

Whenever it stops working I follow this sequence, which you can match
to the logs.

1) Exit cu by ~.
   - if this does not work
       try \r~.
       - if this does not work
          Send SIGHUP, (which so far always worked)

2) Start cu again
   - if it prints leftover characters
     exit cu again by ~. and continue from step 2)

3) If it still not works and hangs again
   - for a few tries  
     unplug PL2303, wait a second replug and goto step 2)


4) If it still does not work
   - Remove PL2303, unload and reload usb (all) and
     plug PL2303 again
   - If module unloading fails, or interrupts died 
       (no response to plugging) > reboot 



Regards
Michael