[PATCH 5.4 157/165] net: dsa: mv88e6xxx: force cmode write on 6141/6341

Greg Kroah-Hartman
2020-01-11T10:34:10Z

From: Baruch Siach <baruch@tkos.co.il>

[ Upstream commit f7a48b68abd9b20ce1ac6298aaaa3c4d158271dd ]

mv88e6xxx_port_set_cmode() relies on cmode stored in struct
mv88e6xxx_port to skip cmode update when the requested value matches the
cached value. It turns out that mv88e6xxx_port_hidden_write() might
change the port cmode setting as a side effect, so we can't rely on the
cached value to determine that cmode update in not necessary.

Force cmode update in mv88e6341_port_set_cmode(), to make
serdes configuration work again. Other mv88e6xxx_port_set_cmode()
callers keep the current behaviour.

This fixes serdes configuration of the 6141 switch on SolidRun Clearfog
GT-8K.

Fixes: 7a3007d22e8 ("net: dsa: mv88e6xxx: fully support SERDES on Topaz family")
Reported-by: Denis Odintsov <d.odintsov@traviangames.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/dsa/mv88e6xxx/port.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

--- a/drivers/net/dsa/mv88e6xxx/port.c
+++ b/drivers/net/dsa/mv88e6xxx/port.c
@@ -393,7 +393,7 @@ phy_interface_t mv88e6390x_port_max_spee
}

static int mv88e6xxx_port_set_cmode(struct mv88e6xxx_chip *chip, int port,
- phy_interface_t mode)
+ phy_interface_t mode, bool force)
{
u8 lane;
u16 cmode;
@@ -427,8 +427,8 @@ static int mv88e6xxx_port_set_cmode(stru
cmode = 0;
}

- /* cmode doesn't change, nothing to do for us */
- if (cmode == chip->ports[port].cmode)
+ /* cmode doesn't change, nothing to do for us unless forced */
+ if (cmode == chip->ports[port].cmode && !force)
return 0;

lane = mv88e6xxx_serdes_get_lane(chip, port);
@@ -484,7 +484,7 @@ int mv88e6390x_port_set_cmode(struct mv8
if (port != 9 && port != 10)
return -EOPNOTSUPP;

- return mv88e6xxx_port_set_cmode(chip, port, mode);
+ return mv88e6xxx_port_set_cmode(chip, port, mode, false);
}

int mv88e6390_port_set_cmode(struct mv88e6xxx_chip *chip, int port,
@@ -504,7 +504,7 @@ int mv88e6390_port_set_cmode(struct mv88
break;
}

- return mv88e6xxx_port_set_cmode(chip, port, mode);
+ return mv88e6xxx_port_set_cmode(chip, port, mode, false);
}

static int mv88e6341_port_set_cmode_writable(struct mv88e6xxx_chip *chip,
@@ -555,7 +555,7 @@ int mv88e6341_port_set_cmode(struct mv88
if (err)
return err;

- return mv88e6xxx_port_set_cmode(chip, port, mode);
+ return mv88e6xxx_port_set_cmode(chip, port, mode, true);
}

int mv88e6185_port_get_cmode(struct mv88e6xxx_chip *chip, int port, u8 *cmode)