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>
diff --git a/src/northbridge/intel/sandybridge/northbridge.c b/src/northbridge/intel/sandybridge/northbridge.c
index 76f03f3..ff6849e 100644
--- a/src/northbridge/intel/sandybridge/northbridge.c
+++ b/src/northbridge/intel/sandybridge/northbridge.c
@@ -431,6 +431,11 @@
}
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
@@ -456,9 +461,6 @@
/* Set here before graphics PM init */
MCHBAR32(0x5500) = 0x00100001;
-
- /* Turn off unused devices */
- disable_peg();
}
static void northbridge_enable(device_t dev)
