The read-modify-write of QSYS_TAG_CONFIG from vsc9959_sched_speed_set()
runs unlocked with respect to the other functions that access it, which
are vsc9959_tas_guard_bands_update(), vsc9959_qos_port_tas_set() and
vsc9959_tas_clock_adjust(). All the others are under ocelot->tas_lock,
so move the vsc9959_sched_speed_set() access under that lock as well, to
resolve the concurrency.
Fixes: 55a515b1f5a9 ("net: dsa: felix: drop oversized frames with tc-taprio instead of hanging the port")
Signed-off-by: Vladimir Oltean <[email protected]>
---
drivers/net/dsa/ocelot/felix_vsc9959.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c
index 35ce08b485f3..db0aec807965 100644
--- a/drivers/net/dsa/ocelot/felix_vsc9959.c
+++ b/drivers/net/dsa/ocelot/felix_vsc9959.c
@@ -1741,13 +1741,13 @@ static void vsc9959_sched_speed_set(struct ocelot *ocelot, int port,
break;
}
+ mutex_lock(&ocelot->tas_lock);
+
ocelot_rmw_rix(ocelot,
QSYS_TAG_CONFIG_LINK_SPEED(tas_speed),
QSYS_TAG_CONFIG_LINK_SPEED_M,
QSYS_TAG_CONFIG, port);
- mutex_lock(&ocelot->tas_lock);
-
if (ocelot_port->taprio)
vsc9959_tas_guard_bands_update(ocelot, port);
--
2.34.1