the following patch was just integrated into master: commit 2cb3e3b828285dc7b390d7af1a2917bb9fa6af3f Author: Duncan Laurie dlaurie@chromium.org Date: Tue Feb 11 10:34:06 2014 -0800
lynxpoint: Do not put SerialIO devices into D3Hot in ACPI mode
Remove the bit of code that was putting the SerialIO devices into D3Hot state when they are switched from PCI to ACPI mode. Instead, add the appropriate ACPI Methods to allow the kernel to control the power state of the device.
The problem seems to be that if the device is put in D3Hot state before it is switched from PCI to ACPI mode then it does not properly export its PCI configuration space and cannot be woken back up.
Adding the ACPI Methods for _PS0/_PS3 allows the kernel to transition the device into D0 state only when it is necessary to communicate with the device, then put it back into D3Hot state.
Change-Id: I2384ba10bf47750d1c1a35216169ddeee26881df Signed-off-by: Duncan Laurie dlaurie@chromium.org
See http://review.coreboot.org/5193 for details.
-gerrit