MST simulation ports can be removed either through HPD unplug, which
removes all ports on the branch device or through hpd irq, which
removed individual ports. In the current driver, the mst state
on the topology manager is being cleared prematurely. This results
in incorrect port status values being reported when the usermode
queries the status prior to disabling the corresponding displays.
So in its current state, on a HPD unplug, the display is disabled
but the port objects are not cleaned up and new ports are added
on every replug. On hpd irq, not all references are removed on
the port object and also the connectors are prematurely being
removed from the connector list. Additionally, when the last
port is removed, the mst state is cleared on the topology manager,
which destroys the branch device. Once the branch device is
destroyed, the ports cannot be added anymore and this leaves the
MST driver in an invalid state.
This change adds a new helper to remove the port and update the
connector list. It also moves the clearing of mst state to hpd
disconnect callback where the branch device can be safely destroyed.
Change-Id: I3400006a47cc8ab5876809a19b711e3b26be857c
Signed-off-by: Rajkumar Subbiah <rsubbia@codeaurora.org>
202c7e55c8