Re: [RFC] (almost) booting allyesconfig -- please don't poke super-io without request_region

Hi Jean,

On Tue, Jul 15, 2008 at 2:36 AM, Jean Delvare [off-list ref] wrote:

quoted

Is there any way to use lspci and start at the LPC bridge, then find
the SuperIO chip's IO address? What about ACPI tables? Perhaps probing
logic could look for an LPC bridge before probing certain IO addresses
even if the addresses are not in the LPC bridge config.

I always assumed that there was no way to know in advance if a
Super-I/O (LPC) chip was present or not, let alone the exact model of
the chip. The I/O addresses are decoded by the Super-I/O chip itself,
and in general it has no relation to PCI. And I've never seen ports
0x2e/0x2f nor 0x4e/0x4f listed in /proc/ioports.

But of course if there is a way to know, we should use it. Avoiding
random access to I/O ports, even if they are relatively standard in
this case, is always good.

I looked at my lspci output and did a little researching, and I think
the only thing we can deduce is that there is an LPC bridge, so
looking for a SuperIO is a good idea. If there is no LPC bridge
listed, I can't say whether probing the ports is a good idea or not.

David