Re: Resume on Apple Mac Mini

[Matthew Garrett <mjg59@srcf.ucam.org>]

On Sat, Jun 17, 2006 at 05:35:51PM -0700, Linus Torvalds wrote:

> The thing that does work is to literally just set the SCI_ENABLE bit:
> 
> 	acpi_set_register(ACPI_BITREG_SCI_ENABLE, 1, ACPI_MTX_DO_NOT_LOCK);
> 
> after resume, _not_ the "acpi_enable()".

The ACPI spec says:

"If this is an S2 or S3 wake, then the BIOS restores minimum context of 
the system before jumping to the waking vector. This includes:

...

ACPI registers. SCI_EN bit must be set. All event status/enable bits 
(PM1x_STS, PM1x_EN, GPEx_STS and GPEx_EN) must not be changed by BIOS."

So it seems like either we're doing something slightly wrong on putting 
machines to sleep which is resulting in them waking up without SCI_EN 
being set, or Windows unconditionally enables it and some hardware is 
just broken. Either way, it doesn't seem likely that it'll cause any 
harm.

-- 
Matthew Garrett | mjg59@srcf.ucam.org