> > Driver disconnect() routines need to unlink ALL urbs as well as
> > make sure that no other driver entries (file operations, say) will
> > ever try to use that device again (even while unlinking proceeds).
>
> Then I hope that disconnect() is not called on an irq!
Only in uncommon error recovery situations, AFAIK. That's is a
good reason to use async unlink in disconnect() though.
> ... But if not, then it seems that while it's out,
> disconnect() might get called. When the process runs again, how will it know
> not to use that device?
The driver has its own record for each device, tracking opens and
doing whatever other magic it needs. There's also the usb_device
pointer.
What disconnect() means is: as of this instant, you can't depend on
being able to do I/O with this device any more. And when that
disconnect() returns, the pointer becomes invalid/unusable.
So disconnect() should clear the usb_device pointer in the driver's
record. That'd be one way that all other execution contexts in
the driver (timer, sleeping process/thread, etc) would know that
particular device is disconnected. The driver would free its own
record of device state when the last context stopped using it.
- Dave
_______________________________________________
[EMAIL PROTECTED]
To unsubscribe, use the last form field at:
http://lists.sourceforge.net/lists/listinfo/linux-usb-devel
