disp: msm: sde: configure dest_scaler op_mode for two independent displays

Destination scaler0 and scaler1 when operated in independent mode,
by two built-in independent displays the op_mode gets modified
concurrently and HW flushes new config. This leads to underruns
on both the displays. This change programs the op_mode
correctly to operate ds0 and ds1 independently.

Change-Id: I01a3d4a986e0e7166f8a38b4cf35981d3e434686
Signed-off-by: Jayaprakash Madisetty <quic_jmadiset@quicinc.com>

msm/sde/sde_hw_ds.c

@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
+ * Copyright (c) 2021-2022 Qualcomm Innovation Center, Inc. All rights reserved.
  * Copyright (c) 2017-2020, The Linux Foundation. All rights reserved.
  */
 
@@ -16,8 +17,18 @@ static void sde_hw_ds_setup_opmode(struct sde_hw_ds *hw_ds,
 				u32 op_mode)
 {
 	struct sde_hw_blk_reg_map *hw = &hw_ds->hw;
+	u32 op_mode_val;
 
-	SDE_REG_WRITE(hw, DEST_SCALER_OP_MODE, op_mode);
+	op_mode_val = SDE_REG_READ(hw, DEST_SCALER_OP_MODE);
+
+	if (op_mode)
+		op_mode_val |= op_mode;
+	else if (!op_mode && (op_mode_val & SDE_DS_OP_MODE_DUAL))
+		op_mode_val = 0;
+	else
+		op_mode_val &= ~BIT(hw_ds->idx - DS_0);
+
+	SDE_REG_WRITE(hw, DEST_SCALER_OP_MODE, op_mode_val);
 }
 
 static void sde_hw_ds_setup_scaler3(struct sde_hw_ds *hw_ds,