mb/google/poppy/variant/nautilus: Change SlowSlewRateForSa setting

If switch to VT2 on nautilus, screen flicker appears. We found if we
rollback the change of slew rate setting, then the flicker issue will
be gone: https://review.coreboot.org/c/coreboot/+/22588
But nautilus board needs slew rate tuning to reduce EE noise, so we
decided to change only SlowSlewRateForSa to 2 (Fast/8) instead of
rollback the whole change of the CL:22588. It can remove the flicker on
VT2.

BUG=b:71397040
BRANCH=master
TEST=emerge-nautilus coreboot

Change-Id: Id1d4bd8b1316c02c783de708ec4658e030193a26
Signed-off-by: Seunghwan Kim <sh_.kim@samsung.com>
Reviewed-on: https://review.coreboot.org/23877
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
This commit is contained in:
Seunghwan Kim 2018-02-27 14:27:26 +09:00 committed by Martin Roth
parent 70ba1b7e78
commit 3dd88f175d
1 changed files with 2 additions and 1 deletions

View File

@ -77,7 +77,8 @@ chip soc/intel/skylake
register "FastPkgCRampDisableSa" = "1"
register "SlowSlewRateForIa" = "3" # Fast/16
register "SlowSlewRateForGt" = "3" # Fast/16
register "SlowSlewRateForSa" = "3" # Fast/16
register "SlowSlewRateForSa" = "2" # Fast/8
# VR Settings Configuration for 4 Domains
#+----------------+-------+-------+-------+-------+
#| Domain/Setting | SA | IA | GTUS | GTS |