sensors: Make sync driver more robust

Use a queue now for sync events, this will allow multiple interrupts to be
called before the motion sense task executes. The events (including
timestamps) get stored in a small queue. 8 events for the queue size should
be plenty, most applications will have latency concerns anyway once we
get a couple of queued up events.

Also changed the init function to be a little bit more robust to race
conditions. Added count argument to the "sync" simulation command to test
the queue behavior.

BRANCH=master
BUG=b:73551961, b:67743747
TEST="sync 4" yields 4 events on the AP, whereas before it would only
give the AP the last event.

Change-Id: I9fcb1fb8b35eb5f8ffcc21afbfcb0f0d9bc33804
Signed-off-by: Alexandru M Stan <amstan@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1065149
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>

0 files changed, 0 insertions, 0 deletions