diff mbox series

[RFC,net-next,v4,20/28] net: dsa: qca8k: clear MASTER_EN after phy read/write

Message ID 20210508002920.19945-20-ansuelsmth@gmail.com
State Superseded
Headers show
Series Multiple improvement to qca8k stability | expand

Commit Message

Christian Marangi May 8, 2021, 12:29 a.m. UTC 
Clear MDIO_MASTER_EN bit from MDIO_MASTER_CTRL after read/write
operation. The MDIO_MASTER_EN bit is not reset after read/write
operation and the next operation can be wrongly interpreted by the
switch as a mdio operation. This cause a production of wrong/garbage
data from the switch and underfined bheavior. (random port drop,
unplugged port flagged with link up, wrong port speed)
Also on driver remove the MASTER_CTRL can be left set and cause the
malfunction of any next driver using the mdio device.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
---
 drivers/net/dsa/qca8k.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
index 0c53b6fdf6ee..2e0d2f918efe 100644
--- a/drivers/net/dsa/qca8k.c
+++ b/drivers/net/dsa/qca8k.c
@@ -661,8 +661,14 @@  qca8k_mdio_write(struct qca8k_priv *priv, int port, u32 regnum, u16 data)
 	if (ret)
 		return ret;
 
-	return qca8k_busy_wait(priv, QCA8K_MDIO_MASTER_CTRL,
-		QCA8K_MDIO_MASTER_BUSY);
+	ret = qca8k_busy_wait(priv, QCA8K_MDIO_MASTER_CTRL,
+			      QCA8K_MDIO_MASTER_BUSY);
+
+	/* even if the busy_wait timeouts try to clear the MASTER_EN */
+	qca8k_reg_clear(priv, QCA8K_MDIO_MASTER_CTRL,
+			QCA8K_MDIO_MASTER_EN);
+
+	return ret;
 }
 
 static int
@@ -697,6 +703,10 @@  qca8k_mdio_read(struct qca8k_priv *priv, int port, u32 regnum)
 
 	val &= QCA8K_MDIO_MASTER_DATA_MASK;
 
+	/* even if the busy_wait timeouts try to clear the MASTER_EN */
+	qca8k_reg_clear(priv, QCA8K_MDIO_MASTER_CTRL,
+			QCA8K_MDIO_MASTER_EN);
+
 	return val;
 }