net: dsa: mv88e6xxx: Handle error in serdes_get_regs

If the underlying read operation failed we would end up writing stale
data to the supplied buffer. This would end up with the last
successfully read value repeating. Fix this by only writing the data
when we know the read was good. This will mean that failed values will
return 0xffff.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Chris Packham 2020-11-24 17:34:40 +13:00 committed by Jakub Kicinski
parent 5c19bc8b57
commit 0fd5d79efa
1 changed files with 9 additions and 5 deletions

View File

@ -400,14 +400,16 @@ void mv88e6352_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p)
{
u16 *p = _p;
u16 reg;
int err;
int i;
if (!mv88e6352_port_has_serdes(chip, port))
return;
for (i = 0 ; i < 32; i++) {
mv88e6352_serdes_read(chip, i, &reg);
p[i] = reg;
err = mv88e6352_serdes_read(chip, i, &reg);
if (!err)
p[i] = reg;
}
}
@ -1096,6 +1098,7 @@ void mv88e6390_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p)
u16 *p = _p;
int lane;
u16 reg;
int err;
int i;
lane = mv88e6xxx_serdes_get_lane(chip, port);
@ -1103,8 +1106,9 @@ void mv88e6390_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p)
return;
for (i = 0 ; i < ARRAY_SIZE(mv88e6390_serdes_regs); i++) {
mv88e6390_serdes_read(chip, lane, MDIO_MMD_PHYXS,
mv88e6390_serdes_regs[i], &reg);
p[i] = reg;
err = mv88e6390_serdes_read(chip, lane, MDIO_MMD_PHYXS,
mv88e6390_serdes_regs[i], &reg);
if (!err)
p[i] = reg;
}
}