openwrt/target/linux/ramips/files-4.14/drivers
DENG Qingfang 718e97c5c8 ramips: mt7530 swconfig: fix race condition in register access
[ Upstream commit f99c9cd9c4 ]

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>
(cherry picked from commit f99c9cd9c4)
2021-05-02 14:43:09 +02:00
..
mmc/host/mtk-mmc ramips: drop obsolete sd card driver code 2018-09-06 21:35:53 +02:00
net/ethernet/mediatek ramips: mt7530 swconfig: fix race condition in register access 2021-05-02 14:43:09 +02:00