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authorAngel Pons <th3fanbus@gmail.com>2021-08-30 11:07:05 +0200
committerFelix Held <felix-coreboot@felixheld.de>2021-09-17 01:05:20 +0000
commite1269a7f21ed1cb408f80a9e4cf9616b4cecc135 (patch)
treeb6e3ad544ee404141aec99c96c994a22abfa9e78 /src/mainboard/purism/librem_skl
parent8031abfcc2968d19242168950988d5adff65c426 (diff)
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>
Diffstat (limited to 'src/mainboard/purism/librem_skl')
-rw-r--r--src/mainboard/purism/librem_skl/romstage.c1
1 files changed, 1 insertions, 0 deletions
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];