Hi David,
On Mon, 5 Mar 2007 13:35:20 -0800, David Hubbard wrote:
Alas, I don't think it can work safely. If ACPI doesn't actually
allocate the resource, there is a risk that another driver does so
between the conflict check and the I/O access. I believe this is the
reason why Rudolf used ____request_resource and not __check_region.
In fact Rudolf's solution is nice for LPC chips, however I don't think
it can work with SMBus chips. It might intercept the accesses to the
SMBus master and be able to emulate it, even though this will be more
complex that the W83627EHF case, and I'm not sure about the PCI config
space. But ultimately we need to emulate all the chips behind the
SMBus, too. The drivers for these chips won't know if they are accessed
for real of through the emulation layer, so there is no way they'll
remember states, while they might have to (e.g. the W83781D has a bank
register too.)
The AML lock approach, OTOH, should work fine in all cases as long as
the context doesn't need to be remembered across AML "sections".
--
Jean Delvare
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