usb_charger: disconnect usb switch until connection is debounced

Re-order logic in BC1.2 detection task so that we open the
USB switches immediately upon detecting a connection, then
debounce the connection, then reset the pericom and determine
BC1.2 charger type.

This fixes two problems:
- Problem where host could enumerate dut, detect disconnect,
and then re-enumerate.
- Problem where sometimes dut would detect a host workstation
as a proprietary charger because we weren't delaying long
enough after opening USB switches before triggering pericom
reset.

BUG=chrome-os-partner:47219
BRANCH=smaug
TEST=tested by connecting workstation to ryu (tested both
pluggin in A side first and C side first). Without this patch,
my workstation often see's disconnect and reconnect. With
this change we only get one connect.

Change-Id: I07cc3473ff32953fad3cc6d1db01b86b44969c4e
Signed-off-by: Alec Berg <alecaberg@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/311804
Reviewed-by: Shawn N <shawnn@chromium.org>

0 files changed, 0 insertions, 0 deletions