[PARPORT] Re: keeping up appearances


Philip Blundell (pb@nexus.co.uk)
Mon, 22 Feb 1999 13:29:19 +0000


>When there character for input or output, they won't be dealt with
>until a function (currently the interrupt function) does it.
>
>Thus, for normal use, interrupt are necessary, so you can't disable them.
>When the device is unused, there aren't any interrupts anyway.

Are you saying that the m68k parallel ports just don't work at all without
interrupts, and they use irqs internally for their own purposes? If so, this
is a rather different issue. The high-level parport code is currently built
on the assumption that interrupts are only generated on transitions of the ACK
pin (though it's left rather muddy which edge is the active one).

The idea of disabling irqs was simply so that if the currently active driver
was a polling-mode one, we wouldn't get a flood of useless interrupts.

p.

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This archive was generated by hypermail 2.0b3 on Mon 22 Feb 1999 - 08:52:19 EST