diff options
| author | Sebastian Andrzej Siewior | 2022-08-25 13:36:44 +0200 |
|---|---|---|
| committer | David S. Miller | 2022-08-29 13:02:26 +0100 |
| commit | 3f8ae9fe0409698799e173f698b714f34570b64b (patch) | |
| tree | bf7550925227acac89bd5810c751976bfcd9fe3d /drivers/net | |
| parent | 1bd3a383075c64d638e65d263c9267b08ee7733c (diff) | |
net: dsa: xrs700x: Use irqsave variant for u64 stats update
xrs700x_read_port_counters() updates the stats from a worker using the
u64_stats_update_begin() version. This is okay on 32-UP since on the
reader side preemption is disabled.
On 32bit-SMP the writer can be preempted by the reader at which point
the reader will spin on the seqcount until writer continues and
completes the update.
Assigning the mib_mutex mutex to the underlying seqcount would ensure
proper synchronisation. The API for that on the u64_stats_init() side
isn't available. Since it is the only user, just use disable interrupts
during the update.
Use u64_stats_update_begin_irqsave() on the writer side to ensure an
uninterrupted update.
Fixes: ee00b24f32eb8 ("net: dsa: add Arrow SpeedChips XRS700x driver")
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: George McCollister <george.mccollister@gmail.com>
Cc: Vivien Didelot <vivien.didelot@gmail.com>
Cc: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: George McCollister <george.mccollister@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/dsa/xrs700x/xrs700x.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/net/dsa/xrs700x/xrs700x.c b/drivers/net/dsa/xrs700x/xrs700x.c index 3887ed33c5fe..fa622639d640 100644 --- a/drivers/net/dsa/xrs700x/xrs700x.c +++ b/drivers/net/dsa/xrs700x/xrs700x.c @@ -109,6 +109,7 @@ static void xrs700x_read_port_counters(struct xrs700x *priv, int port) { struct xrs700x_port *p = &priv->ports[port]; struct rtnl_link_stats64 stats; + unsigned long flags; int i; memset(&stats, 0, sizeof(stats)); @@ -138,9 +139,9 @@ static void xrs700x_read_port_counters(struct xrs700x *priv, int port) */ stats.rx_packets += stats.multicast; - u64_stats_update_begin(&p->syncp); + flags = u64_stats_update_begin_irqsave(&p->syncp); p->stats64 = stats; - u64_stats_update_end(&p->syncp); + u64_stats_update_end_irqrestore(&p->syncp, flags); mutex_unlock(&p->mib_mutex); } |