ryu: disconnect usb switches 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 would enumerate ryu, detect disconnect,
and then re-enumerate.
- Problem where sometimes ryu 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: Ib75a1905c528063316c6a4649d9cf1b71b059c6a
Signed-off-by: Alec Berg <alecaberg@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/311853
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
Commit-Queue: Vincent Palatin <vpalatin@chromium.org>

1 files changed, 3 insertions, 4 deletions

diff --git a/board/ryu/board.c b/board/ryu/board.c
index 1e330425b4..05a0dd471a 100644
--- a/board/ryu/board.c
+++ b/board/ryu/board.c
@@ -155,15 +155,14 @@ static void usb_charger_bc12_detect(void)
 
 	/* Debounce pin plug order if we detect a charger */
 	if (device_type || PI3USB9281_CHG_STATUS_ANY(charger_status)) {
-		msleep(USB_CHG_DEBOUNCE_DELAY_MS);
-
 		/* next operation might trigger a detach interrupt */
 		pi3usb9281_disable_interrupts(0);
 		/* Ensure D+/D- are open before resetting */
 		pi3usb9281_set_switch_manual(0, 1);
 		pi3usb9281_set_pins(0, 0);
-		/* Let D+/D- relax to their idle state */
-		msleep(40);
+
+		/* Delay to debounce pin attach order */
+		msleep(USB_CHG_DEBOUNCE_DELAY_MS);
 
 		/* Trigger chip reset to refresh detection registers */
 		pi3usb9281_reset(0);