Re: [PATCH v3 2/3] ACPI / OSL: Allow PCI to be disabled

From: Sinan Kaya
Date: Tue Dec 11 2018 - 16:57:38 EST

On 12/11/2018 4:46 PM, Rafael J. Wysocki wrote:
On Tue, Dec 11, 2018 at 6:37 PM Sinan Kaya <okaya@xxxxxxxxxx> wrote:

On 12/11/2018 12:09 PM, Christoph Hellwig wrote:
On Mon, Dec 10, 2018 at 06:13:14PM +0000, Sinan Kaya wrote:
Getting ready to allow PCI to be disabled with ACPI enabled. Stub
out calls that depend on PCI.

I think you want to skip building at least all of hwpci.c if CONFIG_PCI
is disabled. Or replace that whole stiking pile of crap with something
resembling C code..

I can give it a try but I'm under the impression that we don't touch
ACPICA code in general.

Feel free to correct me.

We don't as a rule, but depending on what the patch looks like, we
might not follow the rule this time.

OK. Good to know. I'll take a stab at it.

I wonder though what we do if some AML wants to access PCI config
space via an opregion in there. Have you thought about that?

Return an error.

AFAIK, ACPI spec says that AML code running on non-existing op-regions to be
discarded last time I checked.

I know Linux is noisy about these.

I did boot QEMU without CONFIG_PCI. There was a bunch of ACPI errors reported
during boot as expected but boot succeeded. There was no hard lockup/failure.