* [9fans] usb panic
@ 2006-09-11 18:06 Michael Teichgräber
2006-09-11 20:48 ` geoff
0 siblings, 1 reply; 2+ messages in thread
From: Michael Teichgräber @ 2006-09-11 18:06 UTC (permalink / raw)
To: 9fans
Hi,
accidently I started usb/usbmouse a second time, when one copy was
already running and handling an (the only) USB mouse. As a result I
got the following panic message:
panic: kernel fault: no user process pc=0xf010051a addr=0x0000003c
dumpstack disabled
cpu0: exiting
I can reproduce it easily on two different machines with the following
steps, even without starting usbmouse a second time, just writing to
the `ctl' file:
% usb/usbd
% usb/usbmouse
The `usbmouse' process is now reading from e.g. /dev/usb1/1/ep1data
% cd /dev/usb1/1
% echo 'ep 1 bulk r 3 32' > ctl # from /sys/src/cmd/usb/misc/usbmouse.c
The `echo' simulates the accidently restarted usb/usbmouse program, it
tries to reconfigure endpoint 1, which is already used by a running program.
An error message: "write error: permission denied" occurs immediately,
and the ep1data file vanished.
If the mouse has not been moved so far, the system is still
running. If I now move the mouse a bit, i.e. generate some traffic on
the endpoint, the panic message occures and the system is halted.
What does this message mean? Is there a way to debug this? (I have not
much experience with debugging on plan 9 so far.)
Michael
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [9fans] usb panic
2006-09-11 18:06 [9fans] usb panic Michael Teichgräber
@ 2006-09-11 20:48 ` geoff
0 siblings, 0 replies; 2+ messages in thread
From: geoff @ 2006-09-11 20:48 UTC (permalink / raw)
To: 9fans
If I get a chance, I may try to reproduce the crash here.
Meanwhile, could you mail me the results of
acid /386/9pc # or whatever kernel you were running
src(0xf010051a)
^ permalink raw reply [flat|nested] 2+ messages in thread
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2006-09-11 18:06 [9fans] usb panic Michael Teichgräber
2006-09-11 20:48 ` geoff
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