[PATCH net-next v2 2/3] net: dsa: microchip: lan937x: disable in-band status support for RGMII interfaces

[Oleksij Rempel <o.rempel@pengutronix.de>]

From: Lucas Stach <l.stach@pengutronix.de>

This driver do not support in-band mode and in case of CPU<->Switch
link, this mode is not working any way. So, disable it otherwise ingress
path of the switch MAC will stay disabled.

Note: lan9372 manual do not document 0xN301 BIT(2) for the RGMII mode
and recommend[1] to disable in-band link status update for the RGMII RX
path by clearing 0xN302 BIT(0). But, 0xN301 BIT(2) seems to work too, so
keep it unified with other KSZ switches.

[1] https://microchip.my.site.com/s/article/LAN937X-The-required-configuration-for-the-external-MAC-port-to-operate-at-RGMII-to-RGMII-1Gbps-link-speed

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
changes v2:
- use ksz_set_xmii() instead of LAN937X specific code
---
 drivers/net/dsa/microchip/ksz_common.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index baa1eeb9a1b04..b074b4bb06296 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -3116,7 +3116,8 @@ static void ksz_set_xmii(struct ksz_device *dev, int port,
 		/* On KSZ9893, disable RGMII in-band status support */
 		if (dev->chip_id == KSZ9893_CHIP_ID ||
 		    dev->chip_id == KSZ8563_CHIP_ID ||
-		    dev->chip_id == KSZ9563_CHIP_ID)
+		    dev->chip_id == KSZ9563_CHIP_ID ||
+		    is_lan937x(dev))
 			data8 &= ~P_MII_MAC_MODE;
 		break;
 	default:
-- 
2.39.2