Commit fa60b816 authored by Vincent Whitchurch's avatar Vincent Whitchurch Committed by David S. Miller
Browse files

net: stmmac: fix handling of zero coalescing tx-usecs 



Setting ethtool -C eth0 tx-usecs 0 is supposed to disable the use of the
coalescing timer but currently it gets programmed with zero delay
instead.

Disable the use of the coalescing timer if tx-usecs is zero by
preventing it from being restarted.  Note that to keep things simple we
don't start/stop the timer when the coalescing settings are changed, but
just let that happen on the next transmit or timer expiry.

Fixes: 8fce3331 ("net: stmmac: Rework coalesce timer and fix multi-queue races")
Signed-off-by: default avatarVincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6eadb0b3

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

+6 −4
Original line number Diff line number Diff line
@@ -2704,9 +2704,7 @@ 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)

		hrtimer_start(&tx_q->txtimer,

			      STMMAC_COAL_TIMER(priv->tx_coal_timer[queue]),

			      HRTIMER_MODE_REL);

		stmmac_tx_timer_arm(priv, queue);



	flags = u64_stats_update_begin_irqsave(&tx_q->txq_stats.syncp);

	tx_q->txq_stats.tx_packets += tx_packets;
@@ -2995,9 +2993,13 @@ static int stmmac_init_dma_engine(struct stmmac_priv *priv) 
static void stmmac_tx_timer_arm(struct stmmac_priv *priv, u32 queue)

{

	struct stmmac_tx_queue *tx_q = &priv->dma_conf.tx_queue[queue];

	u32 tx_coal_timer = priv->tx_coal_timer[queue];



	if (!tx_coal_timer)

		return;



	hrtimer_start(&tx_q->txtimer,

		      STMMAC_COAL_TIMER(priv->tx_coal_timer[queue]),

		      STMMAC_COAL_TIMER(tx_coal_timer),

		      HRTIMER_MODE_REL);

}