Subject: [PATCH AUTOSEL 5.10 25/54] net: enetc: set MAC RX FIFO to recommended value

From: Sasha Levin <[email-masked]>
Date: Tue, 16 Mar 2021 20:56:24 -0400

From: Alex Marginean <[email-masked]>

[ Upstream commit 1b2395dfff5bb40228a187f21f577cd90673d344 ]

On LS1028A, the MAC RX FIFO defaults to the value 2, which is too high
and may lead to RX lock-up under traffic at a rate higher than 6 Gbps.
Set it to 1 instead, as recommended by the hardware design team and by
later versions of the ENETC block guide.

Signed-off-by: Alex Marginean <[email-masked]>
Reviewed-by: Claudiu Manoil <[email-masked]>
Reviewed-by: Jason Liu <[email-masked]>
Signed-off-by: Vladimir Oltean <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 drivers/net/ethernet/freescale/enetc/enetc_hw.h | 2 ++
 drivers/net/ethernet/freescale/enetc/enetc_pf.c | 6 ++++++
 2 files changed, 8 insertions(+)

diff --git a/drivers/net/ethernet/freescale/enetc/enetc_hw.h b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
index 014ca6ae121f..b70a36ff9543 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_hw.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc_hw.h
@@ -232,6 +232,8 @@ enum enetc_bdr_type {TX, RX};
 #define ENETC_PM0_MAXFRM	0x8014
 #define ENETC_SET_TX_MTU(val)	((val) << 16)
 #define ENETC_SET_MAXFRM(val)	((val) & 0xffff)
+#define ENETC_PM0_RX_FIFO	0x801c
+#define ENETC_PM0_RX_FIFO_VAL	1
 
 #define ENETC_PM_IMDIO_BASE	0x8030
 
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pf.c b/drivers/net/ethernet/freescale/enetc/enetc_pf.c
index 796e3d6f23f0..6ebaff9043b8 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_pf.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_pf.c
@@ -495,6 +495,12 @@ static void enetc_configure_port_mac(struct enetc_hw *hw)
 
 	enetc_port_wr(hw, ENETC_PM1_CMD_CFG, ENETC_PM0_CMD_PHY_TX_EN |
 		      ENETC_PM0_CMD_TXP	| ENETC_PM0_PROMISC);
+
+	/* On LS1028A, the MAC RX FIFO defaults to 2, which is too high
+	 * and may lead to RX lock-up under traffic. Set it to 1 instead,
+	 * as recommended by the hardware team.
+	 */
+	enetc_port_wr(hw, ENETC_PM0_RX_FIFO, ENETC_PM0_RX_FIFO_VAL);
 }
 
 static void enetc_mac_config(struct enetc_hw *hw, phy_interface_t phy_mode)
-- 
2.30.1