[RFC PATCH v2 net-next 02/14] net: dsa: mt7530: fix phylink for port 5 and fix port 5 modes

From: arinc9 . unal
Date: Fri Apr 07 2023 - 09:49:07 EST


From: Arınç ÜNAL <arinc.unal@xxxxxxxxxx>

There're two code paths for setting up port 5:

mt7530_setup()
-> mt7530_setup_port5()

mt753x_phylink_mac_config()
-> mt753x_mac_config()
-> mt7530_mac_config()
-> mt7530_setup_port5()

The first code path is supposed to run when PHY muxing is being used. In
this case, port 5 is somewhat of a hidden port. It won't be defined on the
devicetree so phylink can't be used to manage the port.

The second code path used to call mt7530_setup_port5() directly under case
5 on mt7530_phylink_mac_config() before it was moved to mt7530_mac_config()
with 88bdef8be9f6 ("net: dsa: mt7530: Extend device data ready for adding a
new hardware"). mt7530_setup_port5() will never run through this code path
because the current code on mt7530_setup() bypasses phylink for all cases
of port 5.

Fix this by leaving it to phylink if port 5 is used as a CPU, DSA, or user
port. For the cases of PHY muxing or the port being disabled, call
mt7530_setup_port5() directly from mt7530_setup() without involving
phylink.

Move setting the interface and P5_DISABLED mode to a more specific
location. They're supposed to be overwritten if PHY muxing is detected.

Add comments which explain the process.

Tested-by: Arınç ÜNAL <arinc.unal@xxxxxxxxxx>
Signed-off-by: Arınç ÜNAL <arinc.unal@xxxxxxxxxx>
---
drivers/net/dsa/mt7530.c | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 31ef70f0cd12..a00aabe4987e 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -2288,16 +2288,19 @@ mt7530_setup(struct dsa_switch *ds)
return ret;

/* Setup port 5 */
- priv->p5_intf_sel = P5_DISABLED;
- interface = PHY_INTERFACE_MODE_NA;
-
if (!dsa_is_unused_port(ds, 5)) {
+ /* Set the interface selection of port 5 to GMAC5 when it's used
+ * as a CPU, DSA, or user port. Let phylink handle the rest.
+ */
priv->p5_intf_sel = P5_INTF_SEL_GMAC5;
- ret = of_get_phy_mode(dsa_to_port(ds, 5)->dn, &interface);
- if (ret && ret != -ENODEV)
- return ret;
} else {
- /* Scan the ethernet nodes. look for GMAC1, lookup used phy */
+ /* Scan the ethernet nodes. Look for GMAC1, lookup the used PHY.
+ * Set priv->p5_intf_sel to P5_DISABLED first, then overwrite it
+ * if PHY muxing is detected.
+ */
+ priv->p5_intf_sel = P5_DISABLED;
+ interface = PHY_INTERFACE_MODE_NA;
+
for_each_child_of_node(dn, mac_np) {
if (!of_device_is_compatible(mac_np,
"mediatek,eth-mac"))
@@ -2328,6 +2331,8 @@ mt7530_setup(struct dsa_switch *ds)
of_node_put(phy_node);
break;
}
+
+ mt7530_setup_port5(ds, interface);
}

#ifdef CONFIG_GPIOLIB
@@ -2338,8 +2343,6 @@ mt7530_setup(struct dsa_switch *ds)
}
#endif /* CONFIG_GPIOLIB */

- mt7530_setup_port5(ds, interface);
-
/* Flush the FDB table */
ret = mt7530_fdb_cmd(priv, MT7530_FDB_FLUSH, NULL);
if (ret < 0)
--
2.37.2