Re: RFC: outb 0x80 in inb_p, outb_p harmful on some modern AMD64with MCP51 laptops

From: H. Peter Anvin
Date: Tue Dec 11 2007 - 00:59:25 EST


Alan Cox wrote:
In any case, my machine does not have an ISA bus. Why should it? It's a laptop!

Yes it does. The branding spec said "No ISA bus" so it was renamed "LPC"
and hidden internally, but its alive and well.


Well that, plus it was serialized and uses PCI electricals and timing, hence the LPC (Low Pin Count) moniker. Its performance is pretty much exactly ISA, though, and unlike PCI it provides full support for all legacy ISA features like slave DMA.

-hpa
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