[PATCH 5.10 015/188] net: dsa: lantiq_gswip: Let GSWIP automatically set the xMII clock

[Greg Kroah-Hartman]

From: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>

commit 3e6fdeb28f4c331acbd27bdb0effc4befd4ef8e8 upstream.

The xMII interface clock depends on the PHY interface (MII, RMII, RGMII)
as well as the current link speed. Explicitly configure the GSWIP to
automatically select the appropriate xMII interface clock.

This fixes an issue seen by some users where ports using an external
RMII or RGMII PHY were deaf (no RX or TX traffic could be seen). Most
likely this is due to an "invalid" xMII clock being selected either by
the bootloader or hardware-defaults.

Fixes: 14fceff4771e51 ("net: dsa: Add Lantiq / Intel DSA driver for vrx200")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/dsa/lantiq_gswip.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

--- a/drivers/net/dsa/lantiq_gswip.c
+++ b/drivers/net/dsa/lantiq_gswip.c
@@ -811,10 +811,15 @@ static int gswip_setup(struct dsa_switch
 	/* Configure the MDIO Clock 2.5 MHz */
 	gswip_mdio_mask(priv, 0xff, 0x09, GSWIP_MDIO_MDC_CFG1);
 
-	/* Disable the xMII link */
-	for (i = 0; i < priv->hw_info->max_ports; i++)
+	for (i = 0; i < priv->hw_info->max_ports; i++) {
+		/* Disable the xMII link */
 		gswip_mii_mask_cfg(priv, GSWIP_MII_CFG_EN, 0, i);
 
+		/* Automatically select the xMII interface clock */
+		gswip_mii_mask_cfg(priv, GSWIP_MII_CFG_RATE_MASK,
+				   GSWIP_MII_CFG_RATE_AUTO, i);
+	}
+
 	/* enable special tag insertion on cpu port */
 	gswip_switch_mask(priv, 0, GSWIP_FDMA_PCTRL_STEN,
 			  GSWIP_FDMA_PCTRLp(cpu_port));