tree 83c260041fdc5f3d0d8ce712ddb16849260c1b02
parent bbd33ef5c3cc52d4fd52cd6cd7f30ff6f8588aa2
author Brian Norris <briannorris@chromium.org> 1516393461 -0800
committer ChromeOS Commit Bot <chromeos-commit-bot@chromium.org> 1516843115 +0000

ec_sync: Commit NVRAM updates before battery cutoff

Battery cutoff may cause the entire system to lose power, which means
that any uncommitted nvram updates will be lost. This can leave us in a
battery cutoff loop, where we never completely clear the
BATTERY_CUTOFF_REQUEST flag before actually cutting off power.

The only way to escape this potential cutoff loop is if we manage to
cleanly exit to vb2_kernel_cleanup(), where we perform a similar commit.
But this requires us to retain power for some time after
VbExEcBatteryCutOff().

BRANCH=none
BUG=b:70176744
TEST=`crossystem battery_cutoff_request=1` on scarlet, then reboot;
     see battery cutoff; plug in AC and observe whether we reliably boot
     on first attach

Change-Id: I1acf3aaeaf76f97f7603f79dbfef7a24a96f36dc
Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/876783
Reviewed-by: Philip Chen <philipchen@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
(cherry picked from commit b00bf851cdaada874b7c66c6913d0cef0798fcbf)
Reviewed-on: https://chromium-review.googlesource.com/885141
Reviewed-by: Shelley Chen <shchen@chromium.org>
Commit-Queue: Shelley Chen <shchen@chromium.org>
Tested-by: Shelley Chen <shchen@chromium.org>