<<On Thu, 9 Nov 2000 19:31:26 +1100 (EST), Bruce Evans <[EMAIL PROTECTED]> said:

> - pci drivers "know" that pci interrupts are shareable and force
>   RF_SHAREABLE.  Is this required by the pci spec?


> - the isa compatibility code and pcvt force RF_SHAREABLE although isa
>   irqs are rarely shareable.

This is a bug.  I suspect it may be due to code rot, related to the
removal of the ``conflicts'' keyword in config.

> - sio forces !RF_SHAREABLE, but it is possible for sio interrupts to be
>   shared if they aren't fast.

Well, you're welcome to make it do whatever you think is correct.

>   This overloads RF_SHAREABLE to mean that the device driver
>   supports sharing.

Whether sharing is supported should not be an attribute of the device
driver -- all drivers should support interrupt sharing, even in cases
where the underlying hardware is ``known'' not to support it.  (Having
the drivers specify RF_SHAREABLE is a bug I introduced when I did the
first port to new-bus.)  If there are buses which need to be
programmed to enable or disable sharing, that should be handled
through a bus-specific mechanism (preferably automatically).

Timesharing requires co-operation from both device and bus, but this
is a completely different issue.  No drivers currently support
timesharing.  `sio' at a minimum probably should, as it was the
motivating example for adding that feature.  (My laptop has three PnP
sio ports: an internal modem, an external DB-9, and a dual-ported
infrared transceiver.  There are only two interrupts available among


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