net: bcmgenet: improve TX timeout

Dump useful ring statistics along with interrupt status, software
maintained pointers and hardware registers to help troubleshoot TX queue
stalls.

When a timeout occurs, disable TX NAPI for the rings, dump their states
while interrupts are disabled, re-enable interrupts, NAPI and queue flow
control to help with the recovery.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index 6043734ea613bdae8d1a8c0abe7f14719e3a8cbd..b43b2cb9b830bfc64c1586fb4058f06596671f6e 100644 (file)
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -2770,12 +2770,79 @@ static int bcmgenet_close(struct net_device *dev)
        return ret;
 }
 
+static void bcmgenet_dump_tx_queue(struct bcmgenet_tx_ring *ring)
+{
+       struct bcmgenet_priv *priv = ring->priv;
+       u32 p_index, c_index, intsts, intmsk;
+       struct netdev_queue *txq;
+       unsigned int free_bds;
+       unsigned long flags;
+       bool txq_stopped;
+
+       if (!netif_msg_tx_err(priv))
+               return;
+
+       txq = netdev_get_tx_queue(priv->dev, ring->queue);
+
+       spin_lock_irqsave(&ring->lock, flags);
+       if (ring->index == DESC_INDEX) {
+               intsts = ~bcmgenet_intrl2_0_readl(priv, INTRL2_CPU_MASK_STATUS);
+               intmsk = UMAC_IRQ_TXDMA_DONE | UMAC_IRQ_TXDMA_MBDONE;
+       } else {
+               intsts = ~bcmgenet_intrl2_1_readl(priv, INTRL2_CPU_MASK_STATUS);
+               intmsk = 1 << ring->index;
+       }
+       c_index = bcmgenet_tdma_ring_readl(priv, ring->index, TDMA_CONS_INDEX);
+       p_index = bcmgenet_tdma_ring_readl(priv, ring->index, TDMA_PROD_INDEX);
+       txq_stopped = netif_tx_queue_stopped(txq);
+       free_bds = ring->free_bds;
+       spin_unlock_irqrestore(&ring->lock, flags);
+
+       netif_err(priv, tx_err, priv->dev, "Ring %d queue %d status summary\n"
+                 "TX queue status: %s, interrupts: %s\n"
+                 "(sw)free_bds: %d (sw)size: %d\n"
+                 "(sw)p_index: %d (hw)p_index: %d\n"
+                 "(sw)c_index: %d (hw)c_index: %d\n"
+                 "(sw)clean_p: %d (sw)write_p: %d\n"
+                 "(sw)cb_ptr: %d (sw)end_ptr: %d\n",
+                 ring->index, ring->queue,
+                 txq_stopped ? "stopped" : "active",
+                 intsts & intmsk ? "enabled" : "disabled",
+                 free_bds, ring->size,
+                 ring->prod_index, p_index & DMA_P_INDEX_MASK,
+                 ring->c_index, c_index & DMA_C_INDEX_MASK,
+                 ring->clean_ptr, ring->write_ptr,
+                 ring->cb_ptr, ring->end_ptr);
+}
+
 static void bcmgenet_timeout(struct net_device *dev)
 {
        struct bcmgenet_priv *priv = netdev_priv(dev);
+       u32 int0_enable = 0;
+       u32 int1_enable = 0;
+       unsigned int q;
 
        netif_dbg(priv, tx_err, dev, "bcmgenet_timeout\n");
 
+       bcmgenet_disable_tx_napi(priv);
+
+       for (q = 0; q < priv->hw_params->tx_queues; q++)
+               bcmgenet_dump_tx_queue(&priv->tx_rings[q]);
+       bcmgenet_dump_tx_queue(&priv->tx_rings[DESC_INDEX]);
+
+       bcmgenet_tx_reclaim_all(dev);
+
+       for (q = 0; q < priv->hw_params->tx_queues; q++)
+               int1_enable |= (1 << q);
+
+       int0_enable = UMAC_IRQ_TXDMA_DONE;
+
+       /* Re-enable TX interrupts if disabled */
+       bcmgenet_intrl2_0_writel(priv, int0_enable, INTRL2_CPU_MASK_CLEAR);
+       bcmgenet_intrl2_1_writel(priv, int1_enable, INTRL2_CPU_MASK_CLEAR);
+
+       bcmgenet_enable_tx_napi(priv);
+
        dev->trans_start = jiffies;
 
        dev->stats.tx_errors++;