From c936835c1ec6f871f32c9b87a7708700320075b3 Mon Sep 17 00:00:00 2001
From: Peter Dunning <pdunning@solarflare.com>
Date: Wed, 8 Jul 2015 10:05:10 +0100
Subject: sfc: Report TX completions to BQL after all TX events in interrupt

The limit for BQL is updated each time we call
netdev_tx_completed_queue.
Without this patch the BQL limit was updated for every TX event we
see.
The issue was that this only updated the limit to handle the data
we complete in two events as the first event wouldn't show that
enough traffic had been processed between them.

This was OK when interrupt moderation was off but not when it was
on as more data had to be completed in a single interrupt.

The patch changes this so that we do report the completion to BQL
only when all the TX events in the interrupt have been processed.

Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/ethernet/sfc/efx.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

(limited to 'drivers/net/ethernet/sfc/efx.c')

diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index 804b9ad..03bc03b 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -245,11 +245,17 @@ static int efx_check_disabled(struct efx_nic *efx)
  */
 static int efx_process_channel(struct efx_channel *channel, int budget)
 {
+	struct efx_tx_queue *tx_queue;
 	int spent;
 
 	if (unlikely(!channel->enabled))
 		return 0;
 
+	efx_for_each_channel_tx_queue(tx_queue, channel) {
+		tx_queue->pkts_compl = 0;
+		tx_queue->bytes_compl = 0;
+	}
+
 	spent = efx_nic_process_eventq(channel, budget);
 	if (spent && efx_channel_has_rx_queue(channel)) {
 		struct efx_rx_queue *rx_queue =
@@ -259,6 +265,14 @@ static int efx_process_channel(struct efx_channel *channel, int budget)
 		efx_fast_push_rx_descriptors(rx_queue, true);
 	}
 
+	/* Update BQL */
+	efx_for_each_channel_tx_queue(tx_queue, channel) {
+		if (tx_queue->bytes_compl) {
+			netdev_tx_completed_queue(tx_queue->core_txq,
+				tx_queue->pkts_compl, tx_queue->bytes_compl);
+		}
+	}
+
 	return spent;
 }
 
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