disp: msm: dp: destroy mst topology on unplug

On an MST unplug, the MST topology manager state needs to be cleared
so it can properly destroy the current topology. But since the mst
active state is cleared prematurely in the driver, this call is
skipped and on a subsequent plug-in, the topology manager ends up
using stale topology from previous configuration. Incorrect RAD 
values are used for sideband, causing them to fail.

This change fixes the order of operations, so the topology manager
state is properly updated on unplug. It also removes a duplicate
hpd notification to usermode.

Change-Id: Idcff17be113a361a0b58e54d85957f30d1d4e2d6
Signed-off-by: Sandeep Gangadharaiah <sandgang@codeaurora.org>

msm/dp/dp_display.c

@@ -907,7 +907,7 @@ static int dp_display_send_hpd_notification(struct dp_display_private *dp)
 		if (!dp->mst.cbs.hpd)
 			goto skip_wait;
 
-		dp->mst.cbs.hpd(&dp->dp_display, true);
+		dp->mst.cbs.hpd(&dp->dp_display, hpd);
 	}
 
 	if (hpd) {
@@ -1289,21 +1289,18 @@ static void dp_display_process_mst_hpd_low(struct dp_display_private *dp)
 
 		/*
 		 * HPD unplug callflow:
-		 * 1. send hpd unplug event with status=disconnected
-		 * 2. send hpd unplug on base connector so usermode can disable
-		 * all external displays.
-		 * 3. unset mst state in the topology mgr so the branch device
+		 * 1. send hpd unplug on base connector so usermode can disable
+                 * all external displays.
+		 * 2. unset mst state in the topology mgr so the branch device
 		 *  can be cleaned up.
 		 */
-		if (dp->mst.cbs.hpd)
-			dp->mst.cbs.hpd(&dp->dp_display, false);
 
 		if ((dp_display_state_is(DP_STATE_CONNECT_NOTIFIED) ||
 				dp_display_state_is(DP_STATE_ENABLED)))
 			rc = dp_display_send_hpd_notification(dp);
 
-		dp_display_update_mst_state(dp, false);
 		dp_display_set_mst_mgr_state(dp, false);
+		dp_display_update_mst_state(dp, false);
 	}
 
 	DP_MST_DEBUG("mst_hpd_low. mst_active:%d\n", dp->mst.mst_active);