net: stmmac: move TX timer arm after DMA enable

Move TX timer arm call after DMA interrupt is enabled again.

The TX timer arm function changed logic and now is skipped if a napi is
already scheduled. By moving the TX timer arm call after DMA is enabled,
we permit to correctly skip if a DMA interrupt has been fired and a napi
has been scheduled again.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 5124ee8..11055e9 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2543,9 +2543,13 @@ static void stmmac_bump_dma_threshold(struct stmmac_priv *priv, u32 chan)
  * @priv: driver private structure
  * @budget: napi budget limiting this functions packet handling
  * @queue: TX queue index
+ * @pending_packets: signal to arm the TX coal timer
  * Description: it reclaims the transmit resources after transmission completes.
+ * If some packets still needs to be handled, due to TX coalesce, set
+ * pending_packets to true to make NAPI arm the TX coal timer.
  */
-static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue)
+static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue,
+                          bool *pending_packets)
 {
        struct stmmac_tx_queue *tx_q = &priv->dma_conf.tx_queue[queue];
        struct stmmac_txq_stats *txq_stats = &priv->xstats.txq_stats[queue];
@@ -2706,7 +2710,7 @@ static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue)
 
        /* We still have pending packets, let's call for a new scheduling */
        if (tx_q->dirty_tx != tx_q->cur_tx)
-               stmmac_tx_timer_arm(priv, queue);
+               *pending_packets = true;
 
        flags = u64_stats_update_begin_irqsave(&txq_stats->syncp);
        txq_stats->tx_packets += tx_packets;
@@ -5572,6 +5576,7 @@ static int stmmac_napi_poll_tx(struct napi_struct *napi, int budget)
                container_of(napi, struct stmmac_channel, tx_napi);
        struct stmmac_priv *priv = ch->priv_data;
        struct stmmac_txq_stats *txq_stats;
+       bool pending_packets = false;
        u32 chan = ch->index;
        unsigned long flags;
        int work_done;
@@ -5581,7 +5586,7 @@ static int stmmac_napi_poll_tx(struct napi_struct *napi, int budget)
        txq_stats->napi_poll++;
        u64_stats_update_end_irqrestore(&txq_stats->syncp, flags);
 
-       work_done = stmmac_tx_clean(priv, budget, chan);
+       work_done = stmmac_tx_clean(priv, budget, chan, &pending_packets);
        work_done = min(work_done, budget);
 
        if (work_done < budget && napi_complete_done(napi, work_done)) {
@@ -5592,6 +5597,10 @@ static int stmmac_napi_poll_tx(struct napi_struct *napi, int budget)
                spin_unlock_irqrestore(&ch->lock, flags);
        }
 
+       /* TX still have packet to handle, check if we need to arm tx timer */
+       if (pending_packets)
+               stmmac_tx_timer_arm(priv, chan);
+
        return work_done;
 }
 
@@ -5600,6 +5609,7 @@ static int stmmac_napi_poll_rxtx(struct napi_struct *napi, int budget)
        struct stmmac_channel *ch =
                container_of(napi, struct stmmac_channel, rxtx_napi);
        struct stmmac_priv *priv = ch->priv_data;
+       bool tx_pending_packets = false;
        int rx_done, tx_done, rxtx_done;
        struct stmmac_rxq_stats *rxq_stats;
        struct stmmac_txq_stats *txq_stats;
@@ -5616,7 +5626,7 @@ static int stmmac_napi_poll_rxtx(struct napi_struct *napi, int budget)
        txq_stats->napi_poll++;
        u64_stats_update_end_irqrestore(&txq_stats->syncp, flags);
 
-       tx_done = stmmac_tx_clean(priv, budget, chan);
+       tx_done = stmmac_tx_clean(priv, budget, chan, &tx_pending_packets);
        tx_done = min(tx_done, budget);
 
        rx_done = stmmac_rx_zc(priv, budget, chan);
@@ -5641,6 +5651,10 @@ static int stmmac_napi_poll_rxtx(struct napi_struct *napi, int budget)
                spin_unlock_irqrestore(&ch->lock, flags);
        }
 
+       /* TX still have packet to handle, check if we need to arm tx timer */
+       if (tx_pending_packets)
+               stmmac_tx_timer_arm(priv, chan);
+
        return min(rxtx_done, budget - 1);
 }