Some type-c monitors do not immediately assert HPD. If we continue
to boot without HPD asserted, Depthcharge fails to show pictures
on a monitor even if HPD is asserted later.
Also, if an HDMI monitor is connected, no wait is needed. If only
an HDMI monitor is connected, currently the API always loops until
the stopwatch expires.
This patch will make the AP skip DisplayPort wait loop if it detects
an HDMI monitor. And if an HDMI monitor is not detected, the AP will
wait for DisplayPort mode (like before) but also its HPD signal.
This patch also extends the wait loop time-out to 3 seconds.
BUG=b:72387533
BRANCH=none
TEST=Verify firmware screen is displayed even when a type-c monitor
does not immediately assert HPD. Verify if HDMI monitor is connected,
AP does not wait (and firmware screen is displayed on HDMI monitor).
Change-Id: I0e1afdffbebf4caf35bbb792e7f4637fae89fa49
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-on: https://review.coreboot.org/23816
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
d182b63347