[PATCH net v2] net: airoha: Fix loopback mode configuration for GDM2 port

[Lorenzo Bianconi]

Add missing configuration for loopback mode in airhoha_set_gdm2_loopback
routine.

Fixes: 9cd451d414f6e ("net: airoha: Add loopback support for GDM2")
Signed-off-by: Lorenzo Bianconi <lorenzo at kernel.org>
---
Changes in v2:
- Use human readable marcos to configure loopback mode register
- Link to v1: https://lore.kernel.org/r/20251005-airoha-loopback-mode-fix-v1-1-d017f78acf76@kernel.org
---
 drivers/net/ethernet/airoha/airoha_eth.c  | 4 +++-
 drivers/net/ethernet/airoha/airoha_regs.h | 3 +++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
index 81ea01a652b9c545c348ad6390af8be873a4997f..833dd911980b3f698bd7e5f9fd9e2ce131dd5222 100644
--- a/drivers/net/ethernet/airoha/airoha_eth.c
+++ b/drivers/net/ethernet/airoha/airoha_eth.c
@@ -1710,7 +1710,9 @@ static void airhoha_set_gdm2_loopback(struct airoha_gdm_port *port)
 	airoha_fe_wr(eth, REG_GDM_RXCHN_EN(2), 0xffff);
 	airoha_fe_rmw(eth, REG_GDM_LPBK_CFG(2),
 		      LPBK_CHAN_MASK | LPBK_MODE_MASK | LPBK_EN_MASK,
-		      FIELD_PREP(LPBK_CHAN_MASK, chan) | LPBK_EN_MASK);
+		      FIELD_PREP(LPBK_CHAN_MASK, chan) |
+		      LBK_GAP_MODE_MASK | LBK_LEN_MODE_MASK |
+		      LBK_CHAN_MODE_MASK | LPBK_EN_MASK);
 	airoha_fe_rmw(eth, REG_GDM_LEN_CFG(2),
 		      GDM_SHORT_LEN_MASK | GDM_LONG_LEN_MASK,
 		      FIELD_PREP(GDM_SHORT_LEN_MASK, 60) |
diff --git a/drivers/net/ethernet/airoha/airoha_regs.h b/drivers/net/ethernet/airoha/airoha_regs.h
index e1c15c20be8e13197de743d9b590dc80058560a5..69c5a143db8c079be0a6ecf41081cd3f5048c090 100644
--- a/drivers/net/ethernet/airoha/airoha_regs.h
+++ b/drivers/net/ethernet/airoha/airoha_regs.h
@@ -151,6 +151,9 @@
 #define LPBK_LEN_MASK			GENMASK(23, 10)
 #define LPBK_CHAN_MASK			GENMASK(8, 4)
 #define LPBK_MODE_MASK			GENMASK(3, 1)
+#define LBK_GAP_MODE_MASK		BIT(3)
+#define LBK_LEN_MODE_MASK		BIT(2)
+#define LBK_CHAN_MODE_MASK		BIT(1)
 #define LPBK_EN_MASK			BIT(0)
 
 #define REG_GDM_TXCHN_EN(_n)		(GDM_BASE(_n) + 0x24)

---
base-commit: 1b54b0756f051c11f5a5d0fbc1581e0b9a18e2bc
change-id: 20251005-airoha-loopback-mode-fix-3a9c0036017e

Best regards,
-- 
Lorenzo Bianconi <lorenzo at kernel.org>