[PATCH 5.14 064/169] net: enetc: make sure all traffic classes can send large frames

[Greg Kroah-Hartman]

From: Vladimir Oltean <vladimir.oltean@xxxxxxx>

[ Upstream commit e378f4967c8edd64c680f2e279cb646ee06b6f2d ]

The enetc driver does not implement .ndo_change_mtu, instead it
configures the MAC register field PTC{Traffic Class}MSDUR[MAXSDU]
statically to a large value during probe time.

The driver used to configure only the max SDU for traffic class 0, and
that was fine while the driver could only use traffic class 0. But with
the introduction of mqprio, sending a large frame into any other TC than
0 is broken.

This patch fixes that by replicating per traffic class the static
configuration done in enetc_configure_port_mac().

Fixes: cbe9e835946f ("enetc: Enable TC offloading with mqprio")
Reported-by: Richie Pearn <richard.pearn@xxxxxxx>
Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Reviewed-by: <Claudiu Manoil <claudiu.manoil@xxxxxxx>
Link: https://lore.kernel.org/r/20211020173340.1089992-1-vladimir.oltean@xxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ethernet/freescale/enetc/enetc_pf.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pf.c b/drivers/net/ethernet/freescale/enetc/enetc_pf.c
index cf00709caea4..3ac324509f43 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_pf.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_pf.c
@@ -517,10 +517,13 @@ static void enetc_port_si_configure(struct enetc_si *si)
 
 static void enetc_configure_port_mac(struct enetc_hw *hw)
 {
+	int tc;
+
 	enetc_port_wr(hw, ENETC_PM0_MAXFRM,
 		      ENETC_SET_MAXFRM(ENETC_RX_MAXFRM_SIZE));
 
-	enetc_port_wr(hw, ENETC_PTCMSDUR(0), ENETC_MAC_MAXFRM_SIZE);
+	for (tc = 0; tc < 8; tc++)
+		enetc_port_wr(hw, ENETC_PTCMSDUR(tc), ENETC_MAC_MAXFRM_SIZE);
 
 	enetc_port_wr(hw, ENETC_PM0_CMD_CFG, ENETC_PM0_CMD_PHY_TX_EN |
 		      ENETC_PM0_CMD_TXP	| ENETC_PM0_PROMISC);
-- 
2.33.0