charger: Modify manual mode to save desired current/voltage

Previously manual_mode used the current values of voltage/current to
set the desired values for each charge_request() call. Since manual
mode is entered/exited in the host command task, this can easily lead
to a race condition where the charger gets disabled in the host
command task, the reenabled by the charger task. This in turn makes
the ectool chargecontrol idle command unreliable.

This CL replaces manual mode with two variables, manual_voltage and
manual_current. The default values are -1 which means that they are
inactive. When the ectool command 'chargecontrol idle' is executed, it
sets both variables to 0. This then removes the race condition
possibility as each iteration of the charger loop will use
manual_voltage and/or manual_current if not -1.

BRANCH=coral
BUG=b:68364154
TEST=Manual
Executed 'ectool chargecontrol idle' and 'ectool chargecontrol normal'
numerous times and verified that the charging was disabled/resumed
each time as expected. Without this fix the problem could be
reproduced always in less than 10 attempts, typcially less than
5. With this CL charging is disabled reliably each time and I'm not
able to reproduce the problem.

Change-Id: I1ed9cdb42249cdf72ab34dd95b8f42c09d9a490c
Signed-off-by: Scott Collyer <scollyer@google.com>
Reviewed-on: https://chromium-review.googlesource.com/851419
Tested-by: Scott Collyer <scollyer@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Reviewed-by: Shawn N <shawnn@chromium.org>
Commit-Queue: Scott Collyer <scollyer@chromium.org>
(cherry picked from commit b7254f38979f274acc66330905399ff5ddf4129b)
Reviewed-on: https://chromium-review.googlesource.com/922069
Commit-Ready: Daisuke Nojiri <dnojiri@chromium.org>
Tested-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>

0 files changed, 0 insertions, 0 deletions