RFC: i8259.c cleanup

Geert Uytterhoeven geert at linux-m68k.org
Thu Nov 8 08:26:34 EST 2001


On Wed, 7 Nov 2001, Michael Sokolov wrote:
> hollis at austin.ibm.com wrote:
> > Would you say poking the 8259 directly is more "right" than using 0xbffffff0
> > (or equivalent)?
>
> Both methods are equally right. However, the polling method requires knowledge
> only of the 8259s, which is required anyway, while the other method requires
> knowledge of the interrupt acknowledge mechanism. It is also possible for
> somebody to design a machine with 8259s without any interrupt acknowledge
> mechanism at all, the 8259 datasheet will tell you that it has been designed
> for such applications as well.

But because you have 2 cascaded i8259s it's more complex to poll both i8259s
than to read the single magic interrupt acknowledge register.

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds


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