vboot_reference: eliminate redundant call to write protect EC-RO
This patch eliminates the redundant call to WP the EC-RO region as
protecting RW flash implies protecting both RO and RW flash, so the call
to protect RO is redundant. google/rex is currently takes about 17 ms to
lock down the EC:
Additionally, drops argument to choose between RO and RW slot to protect
while calling into `vb2ex_ec_protect()`. It ensures vb2ex_ec_protect()
is explicitly meant for protecting RW regions.
BUG=b:281918204
TEST=Able to build and boot google/rex and observed boot time savings.
517:waiting for EC to allow higher power draw 846,196 (17,297)
Able to reduce that to 10 ms or so by removing the extra call:
517:waiting for EC to allow higher power draw 838,258 (9,719)
Change-Id: I978d106ad6fa1234b7e472d9ffd52d2628b4cbaa
Cq-Depend: chromium: 4584268
Signed-off-by: Subrata Banik <subratabanik@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/4570361
Auto-Submit: Subrata Banik <subratabanik@chromium.org>
Commit-Queue: Subrata Banik <subratabanik@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Tested-by: Subrata Banik <subratabanik@chromium.org>
4 files changed
