Commit e99b1f04 authored Sep 16, 2009 by Dongdong Deng Committed by David S. Miller Sep 16, 2009

b44: the poll handler b44_poll must not enable IRQ unconditionally



net/core/netpoll.c::netpoll_send_skb() calls the poll handler when
it is available. As netconsole can be used from almost any context,
IRQ must not be enabled blindly in the NAPI handler of the driver
which supports netpoll.

Call trace:
netpoll_send_skb()
{
local_irq_save(flags)
  -> netpoll_poll()
    -> poll_napi()
      -> poll_one_napi()
        -> napi->poll()
            -> b44_poll()
local_irq_restore(flags)
}

Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 3933fc95

drivers/net/b44.c

+3 −4

Original line number	Diff line number	Diff line
		@@ -847,23 +847,22 @@ static int b44_poll(struct napi_struct *napi, int budget)
		{
		struct b44 *bp = container_of(napi, struct b44, napi);
		int work_done;
		unsigned long flags;

		spin_lock_irq(&bp->lock);
		spin_lock_irqsave(&bp->lock, flags);

		if (bp->istat & (ISTAT_TX \| ISTAT_TO)) {
		/* spin_lock(&bp->tx_lock); */
		b44_tx(bp);
		/* spin_unlock(&bp->tx_lock); */
		}
		spin_unlock_irq(&bp->lock);
		spin_unlock_irqrestore(&bp->lock, flags);

		work_done = 0;
		if (bp->istat & ISTAT_RX)
		work_done += b44_rx(bp, budget);

		if (bp->istat & ISTAT_ERRORS) {
		unsigned long flags;

		spin_lock_irqsave(&bp->lock, flags);
		b44_halt(bp);
		b44_init_rings(bp);