RE: [PATCH] ACPI: resume: re-enable SCI-enable workaround

Len Brown
2009-05-16T05:49:47Z

> >The BIOS bug workaround mistakenly got disabled
> >when we followed the ACPI specification more closely
> >by ignoring OS updates to that bit.
>
> Not exactly. ACPICA has always preserved the SCI_EN bit. Linux apparently has a "linux-only" patch to ACPICA that disables this.
>
> The recent version of ACPICA change the #define enough such that the patch no longer works.

"We" here means Linux, and thus the description is accurate.

The fact is that in 2.6.29 Linux had
ACPI_PM1_CONTROL_PRESERVED_BITS 0x0200
and when "we" updated it to 0x201 via the ACPICA update,
the workaround in the Linux resume code became a NOP.

-Len