diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c
index 514db7248a5d..8204d55e2d65 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
@@ -72,6 +72,9 @@
 
 #define MAX_PROP_NAME				32
 
+/* Define the assumed distance between lanes for underspecified device trees. */
+#define QMP_PHY_LEGACY_LANE_STRIDE		0x400
+
 struct qmp_phy_init_tbl {
 	unsigned int offset;
 	unsigned int val;
@@ -733,9 +736,6 @@ struct qmp_phy_cfg {
 	bool has_phy_dp_com_ctrl;
 	/* true, if PHY has secondary tx/rx lanes to be configured */
 	bool is_dual_lane_phy;
-	/* Register offset of secondary tx/rx lanes for USB DP combo PHY */
-	unsigned int tx_b_lane_offset;
-	unsigned int rx_b_lane_offset;
 
 	/* true, if PCS block has no separate SW_RESET register */
 	bool no_pcs_sw_reset;
@@ -748,6 +748,8 @@ struct qmp_phy_cfg {
  * @tx: iomapped memory space for lane's tx
  * @rx: iomapped memory space for lane's rx
  * @pcs: iomapped memory space for lane's pcs
+ * @tx2: iomapped memory space for second lane's tx (in dual lane PHYs)
+ * @rx2: iomapped memory space for second lane's rx (in dual lane PHYs)
  * @pcs_misc: iomapped memory space for lane's pcs_misc
  * @pipe_clk: pipe lock
  * @index: lane index
@@ -759,6 +761,8 @@ struct qmp_phy {
 	void __iomem *tx;
 	void __iomem *rx;
 	void __iomem *pcs;
+	void __iomem *tx2;
+	void __iomem *rx2;
 	void __iomem *pcs_misc;
 	struct clk *pipe_clk;
 	unsigned int index;
@@ -975,8 +979,6 @@ static const struct qmp_phy_cfg qmp_v3_usb3phy_cfg = {
 
 	.has_phy_dp_com_ctrl	= true,
 	.is_dual_lane_phy	= true,
-	.tx_b_lane_offset	= 0x400,
-	.rx_b_lane_offset	= 0x400,
 };
 
 static const struct qmp_phy_cfg qmp_v3_usb3_uniphy_cfg = {
@@ -1031,9 +1033,6 @@ static const struct qmp_phy_cfg sdm845_ufsphy_cfg = {
 	.mask_pcs_ready		= PCS_READY,
 
 	.is_dual_lane_phy	= true,
-	.tx_b_lane_offset	= 0x400,
-	.rx_b_lane_offset	= 0x400,
-
 	.no_pcs_sw_reset	= true,
 };
 
@@ -1238,12 +1237,12 @@ static int qcom_qmp_phy_init(struct phy *phy)
 	qcom_qmp_phy_configure(tx, cfg->regs, cfg->tx_tbl, cfg->tx_tbl_num);
 	/* Configuration for other LANE for USB-DP combo PHY */
 	if (cfg->is_dual_lane_phy)
-		qcom_qmp_phy_configure(tx + cfg->tx_b_lane_offset, cfg->regs,
+		qcom_qmp_phy_configure(qphy->tx2, cfg->regs,
 				       cfg->tx_tbl, cfg->tx_tbl_num);
 
 	qcom_qmp_phy_configure(rx, cfg->regs, cfg->rx_tbl, cfg->rx_tbl_num);
 	if (cfg->is_dual_lane_phy)
-		qcom_qmp_phy_configure(rx + cfg->rx_b_lane_offset, cfg->regs,
+		qcom_qmp_phy_configure(qphy->rx2, cfg->regs,
 				       cfg->rx_tbl, cfg->rx_tbl_num);
 
 	qcom_qmp_phy_configure(pcs, cfg->regs, cfg->pcs_tbl, cfg->pcs_tbl_num);
@@ -1615,8 +1614,9 @@ int qcom_qmp_phy_create(struct device *dev, struct device_node *np, int id)
 
 	/*
 	 * Get memory resources for each phy lane:
-	 * Resources are indexed as: tx -> 0; rx -> 1; pcs -> 2; and
-	 * pcs_misc (optional) -> 3.
+	 * Resources are indexed as: tx -> 0; rx -> 1; pcs -> 2.
+	 * For dual lane PHYs: tx2 -> 3, rx2 -> 4, pcs_misc (optional) -> 5
+	 * For single lane PHYs: pcs_misc (optional) -> 3.
 	 */
 	qphy->tx = of_iomap(np, 0);
 	if (!qphy->tx)
@@ -1630,7 +1630,32 @@ int qcom_qmp_phy_create(struct device *dev, struct device_node *np, int id)
 	if (!qphy->pcs)
 		return -ENOMEM;
 
-	qphy->pcs_misc = of_iomap(np, 3);
+	/*
+	 * If this is a dual-lane PHY, then there should be registers for the
+	 * second lane. Some old device trees did not specify this, so fall
+	 * back to old legacy behavior of assuming they can be reached at an
+	 * offset from the first lane.
+	 */
+	if (qmp->cfg->is_dual_lane_phy) {
+		qphy->tx2 = of_iomap(np, 3);
+		qphy->rx2 = of_iomap(np, 4);
+		if (!qphy->tx2 || !qphy->rx2) {
+			dev_warn(dev,
+				 "Underspecified device tree, falling back to legacy register regions\n");
+
+			/* In the old version, pcs_misc is at index 3. */
+			qphy->pcs_misc = qphy->tx2;
+			qphy->tx2 = qphy->tx + QMP_PHY_LEGACY_LANE_STRIDE;
+			qphy->rx2 = qphy->rx + QMP_PHY_LEGACY_LANE_STRIDE;
+
+		} else {
+			qphy->pcs_misc = of_iomap(np, 5);
+		}
+
+	} else {
+		qphy->pcs_misc = of_iomap(np, 3);
+	}
+
 	if (!qphy->pcs_misc)
 		dev_vdbg(dev, "PHY pcs_misc-reg not used\n");