mb/google/rex: Avoid LPDDR5/x hang
This patch avoids random hang issue observed after booted to OS on LPDD5/x platforms due to CLK not tuned properly in SAGV point 0, 2133MT/s.
As per Intel doc 769410 the expected work around is to change SAGV
point 0 from 2133 G4 to 3200 G4.
BUG=b:287170545
TEST=Able to perform 500 power cycles on google/rex without any hang.
Signed-off-by: Subrata Banik <subratabanik@google.com>
Change-Id: I02a9cadc075f396549703d7a008382e76268f865
Reviewed-on: https://review.coreboot.org/c/coreboot/+/76076
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Reviewed-by: Kapil Porwal <kapilporwal@google.com>
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/google/rex/variants/baseboard/rex/devicetree.cb b/src/mainboard/google/rex/variants/baseboard/rex/devicetree.cb
index 5297ce2..0d639e3 100644
--- a/src/mainboard/google/rex/variants/baseboard/rex/devicetree.cb
+++ b/src/mainboard/google/rex/variants/baseboard/rex/devicetree.cb
@@ -41,7 +41,7 @@
register "sagv" = "SAGV_ENABLED"
- register "sagv_freq_mhz[0]" = "2133"
+ register "sagv_freq_mhz[0]" = "3200"
register "sagv_gear[0]" = "4"
register "sagv_freq_mhz[1]" = "6000"