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SubjectRe: Disabling DMA with ICH10?
Date
Arjan van de Ven <arjan@infradead.org> writes:

> a single PIO instruction will NOT be interrupted by an interrupt.
> And can easily take several microseconds (remember: 8Mhz bus
> emulation)

Not that long, there is no emulation there (except for port #80 (hex?)
and similar). Normal 33 MHz access. But it's still slow, of course -
every access takes at least 4(?) bus cycles (IIRC: address, initiator
ready, device selected, target ready). No bursts (at least on typical
x86 hw).

Of course ICH10 AHCI isn't connected with PCI 33/32 bus.

Anyway: PIO = bad idea.
--
Krzysztof Halasa


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