On Mon, Jul 01, 2019 at 12:03:27PM +0200, Antoine Tenart wrote:
> +static irqreturn_t ocelot_ptp_rdy_irq_handler(int irq, void *arg)
> +{
> + struct ocelot *ocelot = arg;
> +
> + do {
> + struct skb_shared_hwtstamps shhwtstamps;
> + struct list_head *pos, *tmp;
> + struct ocelot_skb *entry;
> + struct ocelot_port *port;
> + struct timespec64 ts;
> + struct sk_buff *skb = NULL;
> + u32 val, id, txport;
> +
> + val = ocelot_read(ocelot, SYS_PTP_STATUS);
> +
> + /* Check if a timestamp can be retrieved */
> + if (!(val & SYS_PTP_STATUS_PTP_MESS_VLD))
> + break;
Instead of an infinite do/while loop, I suggest a for loop bounded by
number of iterations or by execution time. That would avoid getting
stuck here forever. After all, this code is an ISR.
Thanks,
Richard
> + WARN_ON(val & SYS_PTP_STATUS_PTP_OVFL);
> +
> + /* Retrieve the ts ID and Tx port */
> + id = SYS_PTP_STATUS_PTP_MESS_ID_X(val);
> + txport = SYS_PTP_STATUS_PTP_MESS_TXPORT_X(val);
> +
> + /* Retrieve its associated skb */
> + port = ocelot->ports[txport];
> +
> + list_for_each_safe(pos, tmp, &port->skbs) {
> + entry = list_entry(pos, struct ocelot_skb, head);
> + if (entry->id != id)
> + continue;
> +
> + skb = entry->skb;
> +
> + list_del(pos);
> + kfree(entry);
> + }
> +
> + /* Next ts */
> + ocelot_write(ocelot, SYS_PTP_NXT_PTP_NXT, SYS_PTP_NXT);
> +
> + if (unlikely(!skb))
> + continue;
> +
> + /* Get the h/w timestamp */
> + ocelot_get_hwtimestamp(ocelot, &ts);
> +
> + /* Set the timestamp into the skb */
> + memset(&shhwtstamps, 0, sizeof(shhwtstamps));
> + shhwtstamps.hwtstamp = ktime_set(ts.tv_sec, ts.tv_nsec);
> + skb_tstamp_tx(skb, &shhwtstamps);
> +
> + dev_kfree_skb_any(skb);
> + } while (true);
> +
> + return IRQ_HANDLED;
> +}
