[NETPOLL]: add retry timeout

Add limited retry logic to netpoll_send_skb

Each time we attempt to send, decrement our per-device retry counter.
On every successful send, we reset the counter. 

We delay 50us between attempts with up to 20000 retries for a total of
1 second. After we've exhausted our retries, subsequent failed
attempts will try only once until reset by success.

Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h
index bcd0ac33f592..be68d94b03d5 100644
--- a/include/linux/netpoll.h
+++ b/include/linux/netpoll.h
@@ -26,6 +26,7 @@ struct netpoll {
 struct netpoll_info {
         spinlock_t poll_lock;
         int poll_owner;
+        int tries;
         int rx_flags;
         spinlock_t rx_lock;
         struct netpoll *rx_np; /* netpoll that registered an rx_hook */