3.10.37-rt38-rc1 stable review patch. If anyone has any objections, please let me know.
------------------ From: Sebastian Andrzej Siewior <[email protected]> What I observe is that the TX queue is not empty and does not make any progress. gfar_clean_tx_ring() does not clean up the packet because it is not completed yet. The root cause is that the DMA engine did not start yet (it was preempted before doing so) and that dumb loop, loops until that packet is gone. This is broken since c233cf4 ("gianfar: Fix tx napi polling"). What remains are spurious interrupts if CPU0 cleans up TX packages and CPU1 returns with IRQ_NONE. Cc: [email protected] Signed-off-by: Sebastian Andrzej Siewior <[email protected]> Signed-off-by: Steven Rostedt <[email protected]> --- drivers/net/ethernet/freescale/gianfar.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c index 5c0efcc..8aecc1d 100644 --- a/drivers/net/ethernet/freescale/gianfar.c +++ b/drivers/net/ethernet/freescale/gianfar.c @@ -132,7 +132,6 @@ static int gfar_poll(struct napi_struct *napi, int budget); static void gfar_netpoll(struct net_device *dev); #endif int gfar_clean_rx_ring(struct gfar_priv_rx_q *rx_queue, int rx_work_limit); -static void gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue); static void gfar_process_frame(struct net_device *dev, struct sk_buff *skb, int amount_pull, struct napi_struct *napi); void gfar_halt(struct net_device *dev); @@ -2475,7 +2474,7 @@ static void gfar_align_skb(struct sk_buff *skb) } /* Interrupt Handler for Transmit complete */ -static void gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue) +static int gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue) { struct net_device *dev = tx_queue->dev; struct netdev_queue *txq; @@ -2856,10 +2855,14 @@ static int gfar_poll(struct napi_struct *napi, int budget) tx_queue = priv->tx_queue[i]; /* run Tx cleanup to completion */ if (tx_queue->tx_skbuff[tx_queue->skb_dirtytx]) { - gfar_clean_tx_ring(tx_queue); - has_tx_work = 1; + int ret; + + ret = gfar_clean_tx_ring(tx_queue); + if (ret) + has_tx_work++; } } + work_done += has_tx_work; for_each_set_bit(i, &gfargrp->rx_bit_map, priv->num_rx_queues) { /* skip queue if not active */ -- 1.8.5.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
