[net-next PATCH 1/1] drivers: net: dsa: qca8k: fix sgmii with some specific switch revision

[Ansuel Smith]

Enable sgmii pll, tx driver and rx chain only on switch revision 1. This
is not needed on later revision and with qca8327 cause the sgmii
connection to not work at all. This is a case with some router that use
the qca8327 switch and have the cpu port 0 using a sgmii connection.
Without this, routers with this specific configuration won't work as the
ports won't be able to communicate with the cpu port with the result of
no traffic.

Signed-off-by: Ansuel Smith <ansuelsmth@xxxxxxxxx>
---
 drivers/net/dsa/qca8k.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
index bda5a9bf4f52..efeed8094865 100644
--- a/drivers/net/dsa/qca8k.c
+++ b/drivers/net/dsa/qca8k.c
@@ -1227,8 +1227,14 @@ qca8k_phylink_mac_config(struct dsa_switch *ds, int port, unsigned int mode,
 		if (ret)
 			return;
 
-		val |= QCA8K_SGMII_EN_PLL | QCA8K_SGMII_EN_RX |
-			QCA8K_SGMII_EN_TX | QCA8K_SGMII_EN_SD;
+		/* SGMII PLL, TX driver and RX chain is only needed in
+		 * switch revision 1, later revision doesn't need this.
+		 */
+		if (priv->switch_revision == 1)
+			val |= QCA8K_SGMII_EN_PLL | QCA8K_SGMII_EN_RX |
+			       QCA8K_SGMII_EN_TX | QCA8K_SGMII_EN_SD;
+		else
+			val |= QCA8K_SGMII_EN_SD;
 
 		if (dsa_is_cpu_port(ds, port)) {
 			/* CPU port, we're talking to the CPU MAC, be a PHY */
-- 
2.32.0