Change in coreboot[master]: nb/sandybridge: Add a kconfig option to ignore XMP max DIMMs

[Vagiz Tarkhanov (Code Review)]

Vagiz Tarkhanov has uploaded this change for review. ( https://review.coreboot.org/21841

Change subject: nb/sandybridge: Add a kconfig option to ignore XMP max DIMMs
......................................................................

nb/sandybridge: Add a kconfig option to ignore XMP max DIMMs

XMP profiles can have a restriction on max supported DIMMs per channel,
but many configurations work with more DIMMs.

This is relevant on mainboards with 2 DIMM slots per channel (usually 4
in total). Populating both slots with DIMMs that support XMP profiles only
with 1 DIMM per channel turns off said XMP profiles.

Change-Id: I1f22d981afcef0ee73785823b0a943cf3d3564e3
Signed-off-by: Vagiz Trakhanov 
---
M src/northbridge/intel/sandybridge/Kconfig
M src/northbridge/intel/sandybridge/raminit.c
2 files changed, 11 insertions(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/41/21841/1

diff --git a/src/northbridge/intel/sandybridge/Kconfig b/src/northbridge/intel/sandybridge/Kconfig
index 1a47f0d..5ffb796 100644
--- a/src/northbridge/intel/sandybridge/Kconfig
+++ b/src/northbridge/intel/sandybridge/Kconfig
@@ -54,6 +54,15 @@
      Disabled by default as it might causes system instability.
      Handle with care!

+config NATIVE_RAMINIT_IGNORE_XMP_MAX_DIMMS
+	bool "Ignore XMP profile max DIMMs per channel"
+	default n
+	depends on USE_NATIVE_RAMINIT
+	help
+	  Ignore the max DIMMs per channel restriciton defined in XMP profiles.
+	  Disabled by default as it might causes system instability.
+	  Handle with care!
+
 config CBFS_SIZE
    hex
    default 0x100000
diff --git a/src/northbridge/intel/sandybridge/raminit.c b/src/northbridge/intel/sandybridge/raminit.c
index bdba748..6e4d63f 100644
--- a/src/northbridge/intel/sandybridge/raminit.c
+++ b/src/northbridge/intel/sandybridge/raminit.c
@@ -230,7 +230,8 @@
    		if (dimm->dimm[channel][slot].dram_type != SPD_MEMORY_TYPE_SDRAM_DDR3) {
    			printram("No valid XMP profile found.\n");
    			spd_decode_ddr3(&dimm->dimm[channel][slot], spd[spd_slot]);
-			} else if (dimms_on_channel > dimm->dimm[channel][slot].dimms_per_channel) {
+			} else if ((dimms_on_channel > dimm->dimm[channel][slot].dimms_per_channel)
+				   && !IS_ENABLED(CONFIG_NATIVE_RAMINIT_IGNORE_XMP_MAX_DIMMS)) {
    			printram("XMP profile supports %u DIMMs, but %u DIMMs are installed.\n",
    					 dimm->dimm[channel][slot].dimms_per_channel,
    					 dimms_on_channel);