Messages in this thread Patch in this message | | | From | Nikita Yushchenko <> | Subject | [PATCH] net: gainfar: fix race between issuing and completing Tx | Date | Fri, 6 Dec 2013 16:35:59 +0400 |
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gfar_poll() checked Tx queue status without locking, thus allowing gfar_start_xmit() to alter it in parallel, which caused hang on every other nfsroot boot with RT enabled.
This patch raises locking from gfar_clean_tx_ring() up to gfar_poll(). With this change applied, hangs are no longer reproduced.
Signed-off-by: Nikita Yushchenko <nyushchenko@dev.rtsoft.ru> --- drivers/net/ethernet/freescale/gianfar.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c index 0343a14..9ac1946 100644 --- a/drivers/net/ethernet/freescale/gianfar.c +++ b/drivers/net/ethernet/freescale/gianfar.c @@ -2499,7 +2499,6 @@ static void gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue) skb_dirtytx = tx_queue->skb_dirtytx; while ((skb = tx_queue->tx_skbuff[skb_dirtytx])) { - unsigned long flags; frags = skb_shinfo(skb)->nr_frags; @@ -2561,9 +2560,7 @@ static void gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue) TX_RING_MOD_MASK(tx_ring_size); howmany++; - spin_lock_irqsave(&tx_queue->txlock, flags); tx_queue->num_txbdfree += nr_txbds; - spin_unlock_irqrestore(&tx_queue->txlock, flags); } /* If we freed a buffer, we can restart transmission, if necessary */ @@ -2838,6 +2835,7 @@ static int gfar_poll(struct napi_struct *napi, int budget) int has_tx_work; unsigned long rstat_rxf; int num_act_queues; + unsigned long flags; /* Clear IEVENT, so interrupts aren't called again * because of the packets that have already arrived @@ -2854,11 +2852,13 @@ static int gfar_poll(struct napi_struct *napi, int budget) has_tx_work = 0; for_each_set_bit(i, &gfargrp->tx_bit_map, priv->num_tx_queues) { tx_queue = priv->tx_queue[i]; + spin_lock_irqsave(&tx_queue->txlock, flags); /* run Tx cleanup to completion */ if (tx_queue->tx_skbuff[tx_queue->skb_dirtytx]) { gfar_clean_tx_ring(tx_queue); has_tx_work = 1; } + spin_unlock_irqrestore(&tx_queue->txlock, flags); } for_each_set_bit(i, &gfargrp->rx_bit_map, priv->num_rx_queues) { -- 1.7.0.1
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