openwrt/target/linux/ramips/files/drivers
DENG Qingfang f99c9cd9c4 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>
2021-04-15 00:00:54 +08:00
..
mmc/host/mtk-mmc
net/ethernet/ralink ramips: mt7530 swconfig: fix race condition in register access 2021-04-15 00:00:54 +08:00