[coreboot] USB problem with Haswell+LynxPointLP motherboards

[Trammell Hudson]

On Tue, Oct 10, 2017 at 02:44:02PM +0000, ron minnich wrote:
> [    0.376881] ACPI Error: Hardware did not enter ACPI mode
> (20160831/evxfevnt-113)
> 
> is this the step where it tries to do an outb to 0xb2 to tell smm we are
> taking over?

Yes, it looks like it is attempting to write to 0xB2:

	acpi_hw_write_port(acpi_gbl_FADT.smi_command,
		(u32) acpi_gbl_FADT.acpi_enable, 8);

Which is in the FACP table:

[030h 0048   4]             SMI Command Port : 000000B2

Since there in no SMM right now, it looks like Linux would be happy if
that value were zero:

        /*
         * ACPI 2.0 clarified that if SMI_CMD in FADT is zero,
         * system does not support mode transition.
         */
        if (!acpi_gbl_FADT.smi_command) {
                return_UINT32(ACPI_SYS_MODE_ACPI);
        }

(this is getting a little further afield from the Haswell USB problems...)

-- 
Trammell