touch_updater: execute updates in parallel
Executing touch firmware updates synchronously can slow down boot on devices
that have multiple touch devices to update, since the UI will not start
until touch firmware updates are complete.
This patch will run updates in parallel, and then block the upstart job from
completing until the subshells running the firmware updates are all finished.
BUG=chrome-os-partner:57781
TEST=kevin boots to login-prompt-visible ~250-300ms faster
Change-Id: Ie229c0d3c4a930015ace1257c17fbdbbb738930b
Reviewed-on: https://chromium-review.googlesource.com/390334
Commit-Ready: Stephen Barber <smbarber@chromium.org>
Tested-by: Stephen Barber <smbarber@chromium.org>
Reviewed-by: Benson Leung <bleung@chromium.org>
Reviewed-by: Charlie Mooney <charliemooney@chromium.org>
1 file changed
