skylake DDR4 boards: Set `CaVrefConfig` to 2

The `CaVrefConfig` FSP-M UPD describes how the on-die Vref generators
are connected to the DRAM. With the exception of an early Skylake RVP
board (which doesn't have coreboot support), mainboards using DDR3 or
LPDDR3 memory should set `CaVrefConfig` to 0, whereas mainboards with
DDR4 should set `CaVrefConfig` to 2. MRC uses this information during
memory training, so it is important to use the correct value to avoid
any issues, such as increased power usage, system instability or even
boot failures.

However, several Skylake DDR4 mainboards don't set `CaVrefConfig` to 2.
Although they can boot successfully, it's not optimal. For boards that
set `DIMM_SPD_SIZE` to 512 (DDR4 SPD size), set `CaVrefConfig` to 2.

Change-Id: Idab77daff311584b3e3061e9bf107c2fc1b7bdf1
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/57262
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by:  Felix Singer <felixsinger@posteo.net>
Reviewed-by: Michael Niewöhner <foss@mniewoehner.de>

8 files changed, 8 insertions, 0 deletions

diff --git a/src/mainboard/51nb/x210/romstage.c b/src/mainboard/51nb/x210/romstage.c
index 38652b5068..8a8fa4fac6 100644
--- a/src/mainboard/51nb/x210/romstage.c
+++ b/src/mainboard/51nb/x210/romstage.c
@@ -36,6 +36,7 @@ void mainboard_memory_init_params(FSPM_UPD *mupd)
 	mainboard_fill_rcomp_strength_data(&mem_cfg->RcompTarget);
 
 	mem_cfg->DqPinsInterleaved = TRUE;
+	mem_cfg->CaVrefConfig = 2;
 	mem_cfg->MemorySpdDataLen = blk.len;
 	mem_cfg->MemorySpdPtr00 = (uintptr_t) blk.spd_array[0];
 	mem_cfg->MemorySpdPtr10 = (uintptr_t) blk.spd_array[1];
diff --git a/src/mainboard/asrock/h110m/romstage.c b/src/mainboard/asrock/h110m/romstage.c
index f78aa30b21..aec7925772 100644
--- a/src/mainboard/asrock/h110m/romstage.c
+++ b/src/mainboard/asrock/h110m/romstage.c
@@ -22,6 +22,7 @@ void mainboard_memory_init_params(FSPM_UPD *mupd)
 	assert(sizeof(mem_cfg->RcompTarget)   == sizeof(rcomp_targets));
 
 	mem_cfg->DqPinsInterleaved = 1;
+	mem_cfg->CaVrefConfig = 2;
 	get_spd_smbus(&blk);
 	mem_cfg->MemorySpdDataLen = blk.len;
 	mem_cfg->MemorySpdPtr00 = (uintptr_t)blk.spd_array[0];
diff --git a/src/mainboard/clevo/kbl-u/variants/n13xwu/romstage.c b/src/mainboard/clevo/kbl-u/variants/n13xwu/romstage.c
index 4e9d57c21a..116d418f63 100644
--- a/src/mainboard/clevo/kbl-u/variants/n13xwu/romstage.c
+++ b/src/mainboard/clevo/kbl-u/variants/n13xwu/romstage.c
@@ -32,6 +32,7 @@ void variant_configure_fspm(FSPM_UPD *mupd)
 	mainboard_fill_rcomp_strength_data(&mem_cfg->RcompTarget);
 
 	mem_cfg->DqPinsInterleaved = TRUE;
+	mem_cfg->CaVrefConfig = 2;
 	mem_cfg->MemorySpdDataLen = blk.len;
 	mem_cfg->MemorySpdPtr00 = (uintptr_t)blk.spd_array[0];
 	mem_cfg->MemorySpdPtr10 = (uintptr_t)blk.spd_array[1];
diff --git a/src/mainboard/facebook/monolith/romstage.c b/src/mainboard/facebook/monolith/romstage.c
index 0a7a071da1..842724cb20 100644
--- a/src/mainboard/facebook/monolith/romstage.c
+++ b/src/mainboard/facebook/monolith/romstage.c
@@ -19,6 +19,7 @@ void mainboard_memory_init_params(FSPM_UPD *mupd)
 	mainboard_fill_rcomp_strength_data(&mem_cfg->RcompTarget);
 
 	mem_cfg->DqPinsInterleaved = 1;
+	mem_cfg->CaVrefConfig = 2;
 	get_spd_smbus(&blk);
 	mem_cfg->MemorySpdDataLen = blk.len;
 	mem_cfg->MemorySpdPtr00 = (uintptr_t)blk.spd_array[0];
diff --git a/src/mainboard/google/fizz/romstage.c b/src/mainboard/google/fizz/romstage.c
index 85475e5411..5df33daf22 100644
--- a/src/mainboard/google/fizz/romstage.c
+++ b/src/mainboard/google/fizz/romstage.c
@@ -27,6 +27,7 @@ void mainboard_memory_init_params(FSPM_UPD *mupd)
 		.addr_map = { 0x50, 0x52, },
 	};
 	mem_cfg->DqPinsInterleaved = 1;
+	mem_cfg->CaVrefConfig = 2;
 	get_spd_smbus(&blk);
 	mem_cfg->MemorySpdDataLen = blk.len;
 	mem_cfg->MemorySpdPtr00 = (uintptr_t)blk.spd_array[0];
diff --git a/src/mainboard/kontron/bsl6/romstage.c b/src/mainboard/kontron/bsl6/romstage.c
index f38734c25c..b77073ca96 100644
--- a/src/mainboard/kontron/bsl6/romstage.c
+++ b/src/mainboard/kontron/bsl6/romstage.c
@@ -37,6 +37,7 @@ void mainboard_memory_init_params(FSPM_UPD *mupd)
 	       sizeof(memory_params->RcompTarget));
 
 	memory_params->DqPinsInterleaved = true;
+	memory_params->CaVrefConfig = 2;
 
 	const uint8_t ht = get_uint_option("hyper_threading", memory_params->HyperThreading);
 	memory_params->HyperThreading = ht;
diff --git a/src/mainboard/purism/librem_skl/romstage.c b/src/mainboard/purism/librem_skl/romstage.c
index 1c907716c4..604db60e61 100644
--- a/src/mainboard/purism/librem_skl/romstage.c
+++ b/src/mainboard/purism/librem_skl/romstage.c
@@ -29,6 +29,7 @@ void mainboard_memory_init_params(FSPM_UPD *mupd)
 	memcpy(mem_cfg->RcompTarget,   rcomp_targets,   sizeof(mem_cfg->RcompTarget));
 
 	mem_cfg->DqPinsInterleaved = TRUE;
+	mem_cfg->CaVrefConfig = 2;
 	mem_cfg->MemorySpdDataLen = blk.len;
 	mem_cfg->MemorySpdPtr00 = (uintptr_t) blk.spd_array[0];
 
diff --git a/src/mainboard/supermicro/x11-lga1151-series/romstage.c b/src/mainboard/supermicro/x11-lga1151-series/romstage.c
index 67636575ce..b4347d9df9 100644
--- a/src/mainboard/supermicro/x11-lga1151-series/romstage.c
+++ b/src/mainboard/supermicro/x11-lga1151-series/romstage.c
@@ -13,6 +13,7 @@ void mainboard_memory_init_params(FSPM_UPD *mupd)
 	};
 
 	mem_cfg->DqPinsInterleaved = 1;
+	mem_cfg->CaVrefConfig = 2;
 	get_spd_smbus(&blk);
 	mem_cfg->MemorySpdDataLen = blk.len;
 	mem_cfg->MemorySpdPtr00 = (uintptr_t)blk.spd_array[0];