[PATCH net-next 1/2] net: lan743x: add RMII strap status detection for PCI11x1x

From: Thangaraj Samynathan

Date: Fri Mar 27 2026 - 01:42:05 EST


Extend pci11x1x_strap_get_status() to read the RMII strap bits from
the STRAP_READ register. The is_rmii_en flag is initialized to
false and updated based on the hardware strap only if SGMII is not
already enabled. This ensures correct interface identification during
adapter initialization.

Signed-off-by: Thangaraj Samynathan <thangaraj.s@xxxxxxxxxxxxx>
---
drivers/net/ethernet/microchip/lan743x_main.c | 7 +++++++
drivers/net/ethernet/microchip/lan743x_main.h | 3 +++
2 files changed, 10 insertions(+)

diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c
index b4cabde6625a..b7b1584d867d 100644
--- a/drivers/net/ethernet/microchip/lan743x_main.c
+++ b/drivers/net/ethernet/microchip/lan743x_main.c
@@ -42,6 +42,7 @@ static void pci11x1x_strap_get_status(struct lan743x_adapter *adapter)
u32 strap;
int ret;

+ adapter->is_rmii_en = false;
/* Timeout = 100 (i.e. 1 sec (10 msce * 100)) */
ret = lan743x_hs_syslock_acquire(adapter, 100);
if (ret < 0) {
@@ -73,6 +74,12 @@ static void pci11x1x_strap_get_status(struct lan743x_adapter *adapter)
adapter->is_sgmii_en = false;
}
}
+
+ if (!adapter->is_sgmii_en && strap & STRAP_READ_USE_RMII_EN_) {
+ if (strap & STRAP_READ_RMII_EN_)
+ adapter->is_rmii_en = true;
+ }
+
netif_dbg(adapter, drv, adapter->netdev,
"SGMII I/F %sable\n", adapter->is_sgmii_en ? "En" : "Dis");
}
diff --git a/drivers/net/ethernet/microchip/lan743x_main.h b/drivers/net/ethernet/microchip/lan743x_main.h
index 160d94a7cee6..1d7d37456553 100644
--- a/drivers/net/ethernet/microchip/lan743x_main.h
+++ b/drivers/net/ethernet/microchip/lan743x_main.h
@@ -36,7 +36,9 @@
#define FPGA_SGMII_OP BIT(24)

#define STRAP_READ (0x0C)
+#define STRAP_READ_USE_RMII_EN_ BIT(23)
#define STRAP_READ_USE_SGMII_EN_ BIT(22)
+#define STRAP_READ_RMII_EN_ BIT(7)
#define STRAP_READ_SGMII_EN_ BIT(6)
#define STRAP_READ_SGMII_REFCLK_ BIT(5)
#define STRAP_READ_SGMII_2_5G_ BIT(4)
@@ -1071,6 +1073,7 @@ struct lan743x_adapter {
struct lan743x_rx rx[LAN743X_USED_RX_CHANNELS];
bool is_pci11x1x;
bool is_sgmii_en;
+ bool is_rmii_en;
/* protect ethernet syslock */
spinlock_t eth_syslock_spinlock;
bool eth_syslock_en;
--
2.34.1