The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 9fde506e0c53b8309f69b18b4b8144c544b4b3b1 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean <vladimir.oltean@xxxxxxx> Date: Tue, 12 Oct 2021 14:40:37 +0300 Subject: [PATCH] net: mscc: ocelot: warn when a PTP IRQ is raised for an unknown skb When skb_match is NULL, it means we received a PTP IRQ for a timestamp ID that the kernel has no idea about, since there is no skb in the timestamping queue with that timestamp ID. This is a grave error and not something to just "continue" over. So print a big warning in case this happens. Also, move the check above ocelot_get_hwtimestamp(), there is no point in reading the full 64-bit current PTP time if we're not going to do anything with it anyway for this skb. Fixes: 4e3b0468e6d7 ("net: mscc: PTP Hardware Clock (PHC) support") Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx> Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c index 9c62f1d13adc..687c07c338cd 100644 --- a/drivers/net/ethernet/mscc/ocelot.c +++ b/drivers/net/ethernet/mscc/ocelot.c @@ -747,12 +747,12 @@ void ocelot_get_txtstamp(struct ocelot *ocelot) spin_unlock_irqrestore(&port->tx_skbs.lock, flags); + if (WARN_ON(!skb_match)) + continue; + /* Get the h/w timestamp */ ocelot_get_hwtimestamp(ocelot, &ts); - if (unlikely(!skb_match)) - continue; - /* Set the timestamp into the skb */ memset(&shhwtstamps, 0, sizeof(shhwtstamps)); shhwtstamps.hwtstamp = ktime_set(ts.tv_sec, ts.tv_nsec);