diff options
| author | Rob Herring <rob.herring@calxeda.com> | 2012-07-09 14:16:08 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-07-10 23:25:47 -0700 |
| commit | 7c4009192ea2276c1d7ed8ec0a18f3ecfca5cd2b (patch) | |
| tree | 1e330cbaa55ba4af281c3876b5b3c3317378671c /drivers/net/ethernet/calxeda | |
| parent | eb5e1b29a5ff4b782796ec9d17b443b5b38b7ffe (diff) | |
| download | linux-7c4009192ea2276c1d7ed8ec0a18f3ecfca5cd2b.tar.bz2 | |
net: calxedaxgmac: fix hang on rx refill
Fix intermittent hangs in xgmac_rx_refill. If a ring buffer entry already
had an skb allocated, then xgmac_rx_refill would get stuck in a loop. This
can happen on a rx error when we just leave the skb allocated to the entry.
[ 7884.510000] INFO: rcu_preempt detected stall on CPU 0 (t=727315 jiffies)
[ 7884.510000] [<c0010a59>] (unwind_backtrace+0x1/0x98) from [<c006fd93>] (__rcu_pending+0x11b/0x2c4)
[ 7884.510000] [<c006fd93>] (__rcu_pending+0x11b/0x2c4) from [<c0070b95>] (rcu_check_callbacks+0xed/0x1a8)
[ 7884.510000] [<c0070b95>] (rcu_check_callbacks+0xed/0x1a8) from [<c0036abb>] (update_process_times+0x2b/0x48)
[ 7884.510000] [<c0036abb>] (update_process_times+0x2b/0x48) from [<c004e8fd>] (tick_sched_timer+0x51/0x94)
[ 7884.510000] [<c004e8fd>] (tick_sched_timer+0x51/0x94) from [<c0045527>] (__run_hrtimer+0x4f/0x1e8)
[ 7884.510000] [<c0045527>] (__run_hrtimer+0x4f/0x1e8) from [<c0046003>] (hrtimer_interrupt+0xd7/0x1e4)
[ 7884.510000] [<c0046003>] (hrtimer_interrupt+0xd7/0x1e4) from [<c00101d3>] (twd_handler+0x17/0x24)
[ 7884.510000] [<c00101d3>] (twd_handler+0x17/0x24) from [<c006be39>] (handle_percpu_devid_irq+0x59/0x114)
[ 7884.510000] [<c006be39>] (handle_percpu_devid_irq+0x59/0x114) from [<c0069aab>] (generic_handle_irq+0x17/0x2c)
[ 7884.510000] [<c0069aab>] (generic_handle_irq+0x17/0x2c) from [<c000cc8d>] (handle_IRQ+0x35/0x7c)
[ 7884.510000] [<c000cc8d>] (handle_IRQ+0x35/0x7c) from [<c033b153>] (__irq_svc+0x33/0xb8)
[ 7884.510000] [<c033b153>] (__irq_svc+0x33/0xb8) from [<c0244b06>] (xgmac_rx_refill+0x3a/0x140)
[ 7884.510000] [<c0244b06>] (xgmac_rx_refill+0x3a/0x140) from [<c02458ed>] (xgmac_poll+0x265/0x3bc)
[ 7884.510000] [<c02458ed>] (xgmac_poll+0x265/0x3bc) from [<c029fcbf>] (net_rx_action+0xc3/0x200)
[ 7884.510000] [<c029fcbf>] (net_rx_action+0xc3/0x200) from [<c0030cab>] (__do_softirq+0xa3/0x1bc)
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/calxeda')
| -rw-r--r-- | drivers/net/ethernet/calxeda/xgmac.c | 27 |
1 files changed, 12 insertions, 15 deletions
diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c index c4fd2e3600c7..3ca1d792f718 100644 --- a/drivers/net/ethernet/calxeda/xgmac.c +++ b/drivers/net/ethernet/calxeda/xgmac.c @@ -671,26 +671,23 @@ static void xgmac_rx_refill(struct xgmac_priv *priv) p = priv->dma_rx + entry; - if (priv->rx_skbuff[entry] != NULL) - continue; - - skb = __skb_dequeue(&priv->rx_recycle); - if (skb == NULL) - skb = netdev_alloc_skb(priv->dev, priv->dma_buf_sz); - if (unlikely(skb == NULL)) - break; - - priv->rx_skbuff[entry] = skb; - paddr = dma_map_single(priv->device, skb->data, - priv->dma_buf_sz, DMA_FROM_DEVICE); - desc_set_buf_addr(p, paddr, priv->dma_buf_sz); + if (priv->rx_skbuff[entry] == NULL) { + skb = __skb_dequeue(&priv->rx_recycle); + if (skb == NULL) + skb = netdev_alloc_skb(priv->dev, priv->dma_buf_sz); + if (unlikely(skb == NULL)) + break; + + priv->rx_skbuff[entry] = skb; + paddr = dma_map_single(priv->device, skb->data, + priv->dma_buf_sz, DMA_FROM_DEVICE); + desc_set_buf_addr(p, paddr, priv->dma_buf_sz); + } netdev_dbg(priv->dev, "rx ring: head %d, tail %d\n", priv->rx_head, priv->rx_tail); priv->rx_head = dma_ring_incr(priv->rx_head, DMA_RX_RING_SZ); - /* Ensure descriptor is in memory before handing to h/w */ - wmb(); desc_set_rx_owner(p); } } |