nb/intel/sandybridge: Fix PEG disablement

Fix regression introduced by:
3660c0fc65
"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>
This commit is contained in:
Patrick Rudolph 2015-10-21 18:05:01 +02:00 committed by Nico Huber
parent 240766af02
commit aad34cda4b
1 changed files with 5 additions and 3 deletions

View File

@ -438,6 +438,11 @@ static void northbridge_init(struct device *dev)
}
MCHBAR32(0x5f10) = bridge_type;
/* Turn off unused devices. Has to be done before
* setting BIOS_RESET_CPL.
*/
disable_peg();
/*
* Set bit 0 of BIOS_RESET_CPL to indicate to the CPU
* that BIOS has initialized memory and power management
@ -463,9 +468,6 @@ static void northbridge_init(struct device *dev)
/* Set here before graphics PM init */
MCHBAR32(0x5500) = 0x00100001;
/* Turn off unused devices */
disable_peg();
}
static void northbridge_enable(device_t dev)