tree f7b703fa6db342d17804299632604ec18eb956a7
parent ca374d34ed9246baf4fef97214bedd4c16c105a5
author Patrick Rudolph <siro@das-labor.org> 1445443501 +0200
committer Nico Huber <nico.h@gmx.de> 1452802820 +0100

nb/intel/sandybridge: Fix PEG disablement

Fix regression introduced by:
3660c0fc658e4e20ef079f762dfc7ad05c83544c
"northbridge/intel/sandybridge: Enable PEG clock-gating on demand"

Issue observed:
GNU/Linux kernel crashes in earlyinit on systems without PEG devices.
The crash occurs on every boot in different functions.
There's no problem on systems with PEG enabled.

Test system:
 * Lenovo T530
 * Intel Core i5-3320M CPU
 * Fedora GNU/Linux 4.1
 * PEG disabled in devicetree

Problem description:
Tests shows that modifing PEG chicken bit or device enable bits
after setting BIOS_RESET_CPL causes random crashes in GNU/Linux.

Problem solution:
Disable PEG devices before setting BIOS_RESET_CPL.

Final testing results:
No more random kernel crashes.

Change-Id: I4a967c2d00d7d1e4426cf5abdd5f616c21557da7
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: http://review.coreboot.org/12112
Tested-by: build bot (Jenkins)
Reviewed-by: Nico Huber <nico.h@gmx.de>
(cherry picked from commit aad34cda4bc9c14ed10b00fe5da3f32233257913)
Reviewed-on: https://review.coreboot.org/12456
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>