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| author | DENG Qingfang <dqfext@gmail.com> | 2021-04-03 22:59:15 +0800 |
|---|---|---|
| committer | Chuanhong Guo <gch981213@gmail.com> | 2021-04-15 00:00:54 +0800 |
| commit | f99c9cd9c4d4c49a676d678327546fd41690fe2a (patch) | |
| tree | 6976653d304444fb5ef5c4a45ecc7f167038da98 | |
| parent | 679c557e9121f3609346a9f9926130a4e99f18de (diff) | |
| download | upstream-f99c9cd9c4d4c49a676d678327546fd41690fe2a.tar.gz upstream-f99c9cd9c4d4c49a676d678327546fd41690fe2a.tar.bz2 upstream-f99c9cd9c4d4c49a676d678327546fd41690fe2a.zip | |
ramips: mt7530 swconfig: fix race condition in register access
The mt7530_{r,w}32 operation over MDIO uses 3 mdiobus operations and
does not hold a lock, which causes a race condition when multiple
threads try to access a register, they may get unexpected results.
To avoid this, handle the MDIO lock manually, and use the unlocked
__mdiobus_{read,write} in the critical section.
This fixes the "Ghost VLAN" artifact[1] in MT7530/7621 when the VLAN
operation and the swconfig LED link status poll race between each other.
[1] https://forum.openwrt.org/t/mysterious-vlan-ids-on-mt7621-device/64495
Signed-off-by: DENG Qingfang <dqfext@gmail.com>
| -rw-r--r-- | target/linux/ramips/files/drivers/net/ethernet/ralink/mt7530.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/target/linux/ramips/files/drivers/net/ethernet/ralink/mt7530.c b/target/linux/ramips/files/drivers/net/ethernet/ralink/mt7530.c index be1b8a6d8e..b4632d3990 100644 --- a/target/linux/ramips/files/drivers/net/ethernet/ralink/mt7530.c +++ b/target/linux/ramips/files/drivers/net/ethernet/ralink/mt7530.c @@ -290,9 +290,11 @@ mt7530_r32(struct mt7530_priv *priv, u32 reg) if (priv->bus) { u16 high, low; - mdiobus_write(priv->bus, 0x1f, 0x1f, (reg >> 6) & 0x3ff); - low = mdiobus_read(priv->bus, 0x1f, (reg >> 2) & 0xf); - high = mdiobus_read(priv->bus, 0x1f, 0x10); + mutex_lock(&priv->bus->mdio_lock); + __mdiobus_write(priv->bus, 0x1f, 0x1f, (reg >> 6) & 0x3ff); + low = __mdiobus_read(priv->bus, 0x1f, (reg >> 2) & 0xf); + high = __mdiobus_read(priv->bus, 0x1f, 0x10); + mutex_unlock(&priv->bus->mdio_lock); return (high << 16) | (low & 0xffff); } @@ -307,9 +309,11 @@ static void mt7530_w32(struct mt7530_priv *priv, u32 reg, u32 val) { if (priv->bus) { - mdiobus_write(priv->bus, 0x1f, 0x1f, (reg >> 6) & 0x3ff); - mdiobus_write(priv->bus, 0x1f, (reg >> 2) & 0xf, val & 0xffff); - mdiobus_write(priv->bus, 0x1f, 0x10, val >> 16); + mutex_lock(&priv->bus->mdio_lock); + __mdiobus_write(priv->bus, 0x1f, 0x1f, (reg >> 6) & 0x3ff); + __mdiobus_write(priv->bus, 0x1f, (reg >> 2) & 0xf, val & 0xffff); + __mdiobus_write(priv->bus, 0x1f, 0x10, val >> 16); + mutex_unlock(&priv->bus->mdio_lock); return; } |