From: Chris Packham Date: Tue, 24 Nov 2020 04:34:40 +0000 (+1300) Subject: net: dsa: mv88e6xxx: Handle error in serdes_get_regs X-Git-Tag: v5.15~2222^2~165^2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0fd5d79efa4a35c5b0944f7dc42b440d56af4b04;p=platform%2Fkernel%2Flinux-starfive.git 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 Reviewed-by: Andrew Lunn Signed-off-by: Jakub Kicinski --- diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c index e60e8f0..3195936 100644 --- a/drivers/net/dsa/mv88e6xxx/serdes.c +++ b/drivers/net/dsa/mv88e6xxx/serdes.c @@ -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, ®); - p[i] = reg; + err = mv88e6352_serdes_read(chip, i, ®); + 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], ®); - p[i] = reg; + err = mv88e6390_serdes_read(chip, lane, MDIO_MMD_PHYXS, + mv88e6390_serdes_regs[i], ®); + if (!err) + p[i] = reg; } }