Merge branch 'fix-iet-verification-implementation-for-cpsw-driver'

Aksh Garg says:

====================
Fix IET verification implementation for CPSW driver

The CPSW module supports Intersperse Express Traffic (IET) and allows
the MAC layer to verify whether the peer supports IET through its MAC
merge sublayer, by sending a verification packet and waiting for its
response until the timeout. As defined in IEEE 802.3 Clause 99, the
verification process involves up to 3 verification attempts to
establish support.

This patch series fixes issues in the implementation of this IET
verification process.
====================

Link: https://patch.msgid.link/20251106092305.1437347-1-a-garg7@ti.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: kuba-moo

drivers/net/ethernet/ti/am65-cpsw-qos.c

@@ -276,9 +276,31 @@ static int am65_cpsw_iet_set_verify_timeout_count(struct am65_cpsw_port *port)
 	/* The number of wireside clocks contained in the verify
 	 * timeout counter. The default is 0x1312d0
 	 * (10ms at 125Mhz in 1G mode).
+	 * The frequency of the clock depends on the link speed
+	 * and the PHY interface.
 	 */
-	val = 125 * HZ_PER_MHZ;	/* assuming 125MHz wireside clock */
+	switch (port->slave.phy_if) {
+	case PHY_INTERFACE_MODE_RGMII:
+	case PHY_INTERFACE_MODE_RGMII_ID:
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+		if (port->qos.link_speed == SPEED_1000)
+			val = 125 * HZ_PER_MHZ;	/* 125 MHz at 1000Mbps*/
+		else if (port->qos.link_speed == SPEED_100)
+			val = 25 * HZ_PER_MHZ;	/* 25 MHz at 100Mbps*/
+		else
+			val = (25 * HZ_PER_MHZ) / 10;	/* 2.5 MHz at 10Mbps*/
+		break;
+
+	case PHY_INTERFACE_MODE_QSGMII:
+	case PHY_INTERFACE_MODE_SGMII:
+		val = 125 * HZ_PER_MHZ;	/* 125 MHz */
+		break;
 
+	default:
+		netdev_err(port->ndev, "selected mode does not supported IET\n");
+		return -EOPNOTSUPP;
+	}
 	val /= MILLIHZ_PER_HZ;		/* count per ms timeout */
 	val *= verify_time_ms;		/* count for timeout ms */
 
@@ -295,20 +317,21 @@ static int am65_cpsw_iet_verify_wait(struct am65_cpsw_port *port)
 	u32 ctrl, status;
 	int try;
 
-	try = 20;
-	do {
-		/* Reset the verify state machine by writing 1
-		 * to LINKFAIL
-		 */
-		ctrl = readl(port->port_base + AM65_CPSW_PN_REG_IET_CTRL);
-		ctrl |= AM65_CPSW_PN_IET_MAC_LINKFAIL;
-		writel(ctrl, port->port_base + AM65_CPSW_PN_REG_IET_CTRL);
+	try = 3;
 
-		/* Clear MAC_LINKFAIL bit to start Verify. */
-		ctrl = readl(port->port_base + AM65_CPSW_PN_REG_IET_CTRL);
-		ctrl &= ~AM65_CPSW_PN_IET_MAC_LINKFAIL;
-		writel(ctrl, port->port_base + AM65_CPSW_PN_REG_IET_CTRL);
+	/* Reset the verify state machine by writing 1
+	 * to LINKFAIL
+	 */
+	ctrl = readl(port->port_base + AM65_CPSW_PN_REG_IET_CTRL);
+	ctrl |= AM65_CPSW_PN_IET_MAC_LINKFAIL;
+	writel(ctrl, port->port_base + AM65_CPSW_PN_REG_IET_CTRL);
 
+	/* Clear MAC_LINKFAIL bit to start Verify. */
+	ctrl = readl(port->port_base + AM65_CPSW_PN_REG_IET_CTRL);
+	ctrl &= ~AM65_CPSW_PN_IET_MAC_LINKFAIL;
+	writel(ctrl, port->port_base + AM65_CPSW_PN_REG_IET_CTRL);
+
+	do {
 		msleep(port->qos.iet.verify_time_ms);
 
 		status = readl(port->port_base + AM65_CPSW_PN_REG_IET_STATUS);
@@ -330,7 +353,7 @@ static int am65_cpsw_iet_verify_wait(struct am65_cpsw_port *port)
 			netdev_dbg(port->ndev, "MAC Merge verify error\n");
 			return -ENODEV;
 		}
-	} while (try-- > 0);
+	} while (--try > 0);
 
 	netdev_dbg(port->ndev, "MAC Merge verify timeout\n");
 	return -ETIMEDOUT;