When a DP cable is attached, if we toggle the USB/DP mux to USB mode,
the DP data link is broken. In this case, we should send a HPD event to
notify the host. Similarily, when we switch back to DP mode when a cable
is attached, we should send a HPD attachment event and then a HPD IRQ to
notify the host that the DP link is ready.
BRANCH=None
BUG=chrome-os-partner:34296
TEST=Connect Plankton to Samus. Perform the following tests:
1. Attach a cable, and switch between USB and DP mode.
2. Attach a cable in DP mode, switch to USB mode, unplug the
cable, and then switch back to DP mode.
3. Similar to 2 but start without the cable.
Change-Id: I5db0c036ce45850b2f4ca142957f4a235673df6f
Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/237604
Reviewed-by: Alec Berg <alecaberg@chromium.org>
Commit-Queue: Todd Broch <tbroch@chromium.org>
Tested-by: Todd Broch <tbroch@chromium.org>
a9099ee3fc