chip/g: prevent USB read queue overflow

CR50 should check whether USB RX queue has enough space
for host data. If not, it schedules to retry it in another
deferred call.

BUG=b:130908211
BRANCH=cr50
TEST=manually ran "echo 'help' > /dev/ttyUSB0" more than 30 times.
Without this CL, it used to break cr50 console input, and it worked as
if it is 'read-only'.
After applying this CL, cr50 console input works normal even after
excessive input stream.

Change-Id: Ieace84b51c31800b52d2c4a9334e6ffe7888e592
Signed-off-by: Namyoon Woo <namyoon@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1576326
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Reviewed-by: Mary Ruthven <mruthven@chromium.org>

0 files changed, 0 insertions, 0 deletions