caif: Fix napi poll list corruption
authorHerbert Xu <herbert@gondor.apana.org.au>
Mon, 22 Dec 2014 09:35:25 +0000 (20:35 +1100)
committerDavid S. Miller <davem@davemloft.net>
Mon, 22 Dec 2014 21:34:39 +0000 (16:34 -0500)
The commit d75b1ade567ffab085e8adbbdacf0092d10cd09c (net: less
interrupt masking in NAPI) breaks caif.

It is now required that if the entire budget is consumed when poll
returns, the napi poll_list must remain empty.  However, like some
other drivers caif tries to do a last-ditch check and if there is
more work it will call napi_schedule and then immediately process
some of this new work.  Should the entire budget be consumed while
processing such new work then we will violate the new caller
contract.

This patch fixes this by not touching any work when we reschedule
in caif.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/caif/caif_virtio.c

index a5fefb9059c592aa5134302ba79f411a2874d65a..b306210b02b7b40c717ae160e4116db8926418ce 100644 (file)
@@ -257,7 +257,6 @@ static int cfv_rx_poll(struct napi_struct *napi, int quota)
        struct vringh_kiov *riov = &cfv->ctx.riov;
        unsigned int skb_len;
 
-again:
        do {
                skb = NULL;
 
@@ -322,7 +321,6 @@ exit:
                    napi_schedule_prep(napi)) {
                        vringh_notify_disable_kern(cfv->vr_rx);
                        __napi_schedule(napi);
-                       goto again;
                }
                break;