Re: [PATCH] x86: provide a DMI based port 0x80 I/O delay override.

From: H. Peter Anvin
Date: Mon Dec 17 2007 - 16:21:49 EST


David P. Reed wrote:

Note that I can run the port 80 test once, the second time I get the hard freeze. I didn't try writing to port 70 from userspace - that one's dangerous, but the reading of it was included for a timing typical of a chipset supported device. These are all pretty consistent.

I find the "read" timing from 0x80 verrrrry interesting. The write timeing is also interesting, being faster than an unused port.


Once again: reading from port 0x80 goes to the DMA page device.

-hpa
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