net: mscc: ocelot: fix race between ndo_get_stats64 and ocelot_check_stats_work

The 2 methods can run concurrently, and one will change the window of
counters (SYS_STAT_CFG_STAT_VIEW) that the other sees. The fix is
similar to what commit 7fbf6795d1 ("net: mscc: ocelot: fix mutex lock
error during ethtool stats read") has done for ethtool -S.

Fixes: a556c76adc ("net: mscc: Add initial Ocelot switch support")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Vladimir Oltean 2022-08-16 16:53:49 +03:00 committed by Jakub Kicinski
parent 22d842e3ef
commit 18d8e67df1

View file

@ -726,6 +726,8 @@ static void ocelot_get_stats64(struct net_device *dev,
struct ocelot *ocelot = priv->port.ocelot;
int port = priv->port.index;
spin_lock(&ocelot->stats_lock);
/* Configure the port to read the stats from */
ocelot_write(ocelot, SYS_STAT_CFG_STAT_VIEW(port),
SYS_STAT_CFG);
@ -758,6 +760,8 @@ static void ocelot_get_stats64(struct net_device *dev,
stats->tx_dropped = ocelot_read(ocelot, SYS_COUNT_TX_DROPS) +
ocelot_read(ocelot, SYS_COUNT_TX_AGING);
stats->collisions = ocelot_read(ocelot, SYS_COUNT_TX_COLLISION);
spin_unlock(&ocelot->stats_lock);
}
static int ocelot_port_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],