disp: msm: sde: override qsync read pointer during IPC

Currently, when there is an idle power collapse HW resets
the internal read pointer value to 0. This causes the trigger
window to be out of sync when power is restored until the
next vsync is received.

This change overrides the internal read pointer value to
the maximum qsync timeout value on restore and defers frame
trigger to next vsync.

Change-Id: Ibdad3f8eb367136ee0d766bed10742a281e36b4e
Signed-off-by: Amine Najahi <[email protected]>

msm/sde/sde_encoder_phys_cmd.c

@@ -1199,7 +1199,9 @@ static void _sde_encoder_phys_cmd_pingpong_config(
 static void sde_encoder_phys_cmd_enable_helper(
 		struct sde_encoder_phys *phys_enc)
 {
+	struct sde_encoder_virt *sde_enc;
 	struct sde_hw_intf *hw_intf;
+	u32 qsync_mode;
 
 	if (!phys_enc || !phys_enc->hw_ctl || !phys_enc->hw_pp ||
 			!phys_enc->hw_intf) {
@@ -1221,6 +1223,19 @@ static void sde_encoder_phys_cmd_enable_helper(
 		hw_intf->ops.enable_wide_bus(hw_intf,
 			sde_encoder_is_widebus_enabled(phys_enc->parent));
 
+	/*
+	* Override internal rd_ptr value when coming out of IPC.
+	* This is required on QSYNC panel with low refresh rate to
+	* avoid out of sync frame trigger as panel rd_ptr was still
+	* incrementing while MDP was power collapsed.
+	*/
+	sde_enc = to_sde_encoder_virt(phys_enc->parent);
+	if (sde_enc->idle_pc_restore) {
+		qsync_mode = sde_connector_get_qsync_mode(phys_enc->connector);
+		if (qsync_mode)
+			sde_encoder_override_tearcheck_rd_ptr(phys_enc);
+	}
+
 	/*
 	 * For pp-split, skip setting the flush bit for the slave intf, since
 	 * both intfs use same ctl and HW will only flush the master.