disp: msm: dp: check panel state before accessing dp audio registers

During DP disable, it is possible for audio and display to race
causing the audio to send teardown notification after display driver
has disabled all the clocks. This change adds a check for panel state to
avoid accessing registers during this callback.

Change-Id: I6322726a04745bc6c73338cd33f65cfdbfe42ec7
Signed-off-by: Nisarg Bhavsar <quic_bhavsar@quicinc.com>

msm/dp/dp_panel.c

@@ -3126,6 +3126,15 @@ int dp_panel_sink_crc_enable(struct dp_panel *dp_panel, bool enable)
 	return rc;
 }
 
+bool dp_panel_get_panel_on(struct dp_panel *dp_panel)
+{
+	struct dp_panel_private *panel;
+
+	panel = container_of(dp_panel, struct dp_panel_private, dp_panel);
+
+	return panel->panel_on;
+}
+
 struct dp_panel *dp_panel_get(struct dp_panel_in *in)
 {
 	int rc = 0;
@@ -3204,6 +3213,7 @@ struct dp_panel *dp_panel_get(struct dp_panel_in *in)
 	dp_panel->get_src_crc = dp_panel_get_src_crc;
 	dp_panel->get_sink_crc = dp_panel_get_sink_crc;
 	dp_panel->sink_crc_enable = dp_panel_sink_crc_enable;
+	dp_panel->get_panel_on = dp_panel_get_panel_on;
 
 	sde_conn = to_sde_connector(dp_panel->connector);
 	sde_conn->drv_panel = dp_panel;