[NETPOLL]: Revert two bogus cleanups that broke netconsole.

Based upon a report by Andrew Morton and code analysis done
by Jarek Poplawski.

This reverts 33f807ba0d9259e7c75c7a2ce8bd2787e5b540c7 ("[NETPOLL]:
Kill NETPOLL_RX_DROP, set but never tested.")  and
c7b6ea24b43afb5749cb704e143df19d70e23dea ("[NETPOLL]: Don't need
rx_flags.").

The rx_flags did get tested for zero vs. non-zero and therefore we do
need those tests and that code which sets NETPOLL_RX_DROP et al.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 3 deletions

diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h
index a0525a1f4715..e3d79593fb3a 100644
--- a/include/linux/netpoll.h
+++ b/include/linux/netpoll.h
@@ -25,6 +25,7 @@ struct netpoll {
 
 struct netpoll_info {
         atomic_t refcnt;
+        int rx_flags;
         spinlock_t rx_lock;
         struct netpoll *rx_np; /* netpoll that registered an rx_hook */
         struct sk_buff_head arp_tx; /* list of arp requests to reply to */
@@ -50,12 +51,12 @@ static inline int netpoll_rx(struct sk_buff *skb)
         unsigned long flags;
         int ret = 0;
 
-        if (!npinfo || !npinfo->rx_np)
+        if (!npinfo || (!npinfo->rx_np && !npinfo->rx_flags))
                 return 0;
 
         spin_lock_irqsave(&npinfo->rx_lock, flags);
-        /* check rx_np again with the lock held */
-        if (npinfo->rx_np && __netpoll_rx(skb))
+        /* check rx_flags again with the lock held */
+        if (npinfo->rx_flags && __netpoll_rx(skb))
                 ret = 1;
         spin_unlock_irqrestore(&npinfo->rx_lock, flags);