Re: S3 resume regression [1cf4f629d9d2 ("cpu/hotplug: Move online calls to hotplugged cpu")]

From: Arjan van de Ven
Date: Wed May 11 2016 - 08:44:20 EST


On 5/11/2016 3:19 AM, Ville Syrjälä wrote:

Oh, and this was with acpi_idle. This machine already failed to
resume from S3 with intel_idle since forever, as detailed in
https://bugzilla.kernel.org/show_bug.cgi?id=107151
but acpi_idle worked fine until now.

this is the important clue part afaics.

some of these very old Atom's had issues (bios?) with S3 if the cores were in a too-deep C state,
and at some point there was a workaround (I forgot where in the code) to ban those deep
C states around S3 on those cpus. I wonder if moving things around has made said workaround
ineffective.....