Re: [PATCH net-next v7 3/3] net: axienet: Introduce dmaengine support

From: Jakub Kicinski
Date: Fri Oct 06 2023 - 17:32:37 EST


On Fri, 6 Oct 2023 19:04:29 +0000 Pandey, Radhey Shyam wrote:
> > > + netif_stop_queue(ndev);
> > > + if (net_ratelimit())
> > > + netdev_warn(ndev, "TX ring unexpectedly full\n");
> >
> > I don't see you stopping the queue when the ring gets full, am I not looking
> > into the right place? Otherwise this is sort of expected to occasionally hapen
>
> We are calling stop_queue if TX ring is full. Is that what you meant?
> netif_stop_queue(ndev);

But somewhere else or just here after printing the warning?

The recommended flow is to stop the queue after enqueuing
a packet successfully, if the remaining space is not enough
to hold an skb with all frags populated. That avoids ever
returning BUSY.