Re: [net-next, v2, 1/2] net: stmmac: Rework coalesce timer and fix multi-queue races

[Neil Armstrong <narmstrong@baylibre.com>]

Hi Jose,

On 10/09/2018 11:14, Jose Abreu wrote:
> This follows David Miller advice and tries to fix coalesce timer in
> multi-queue scenarios.
> 
> We are now using per-queue coalesce values and per-queue TX timer.
> 
> Coalesce timer default values was changed to 1ms and the coalesce frames
> to 25.
> 
> Tested in B2B setup between XGMAC2 and GMAC5.
> 
> Signed-off-by: Jose Abreu <joabreu@synopsys.com>
> Cc: Jerome Brunet <jbrunet@baylibre.com>
> Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> Cc: David S. Miller <davem@davemloft.net>
> Cc: Joao Pinto <jpinto@synopsys.com>
> Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
> Cc: Alexandre Torgue <alexandre.torgue@st.com>
> ---
> Jerome,

Jerome is in holidays...

> 
> Can you please test if this one is okay ?


I tested this patch on top of 4.18.7 with the previous patch (4ae0169fd1b3) reverted.

The TX or RX stopped a few seconds after iperf3 started :
(iperf3 is running in server mode on the Amlogic A113D board)

$ iperf3 -c 10.1.4.95
Connecting to host 10.1.4.95, port 5201
[  4] local 10.1.2.12 port 39906 connected to 10.1.4.95 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec  56.2 MBytes   472 Mbits/sec    0    660 KBytes
[  4]   1.00-2.00   sec  56.2 MBytes   472 Mbits/sec    0    660 KBytes
[  4]   2.00-3.00   sec  38.8 MBytes   325 Mbits/sec    1   1.41 KBytes
[  4]   3.00-4.00   sec  0.00 Bytes  0.00 bits/sec    1   1.41 KBytes
[  4]   4.00-5.00   sec  0.00 Bytes  0.00 bits/sec    1   1.41 KBytes
^C[  4]   5.00-5.61   sec  0.00 Bytes  0.00 bits/sec    0   1.41 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth       Retr
[  4]   0.00-5.61   sec   151 MBytes   226 Mbits/sec    3             sender
[  4]   0.00-5.61   sec  0.00 Bytes  0.00 bits/sec                  receiver
iperf3: interrupt - the client has terminated

$ iperf3 -c 10.1.4.95 -R
Connecting to host 10.1.4.95, port 5201
Reverse mode, remote host 10.1.4.95 is sending
[  4] local 10.1.2.12 port 39894 connected to 10.1.4.95 port 5201
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.00   sec  82.2 MBytes   690 Mbits/sec
[  4]   1.00-2.00   sec  82.6 MBytes   693 Mbits/sec
[  4]   2.00-3.00   sec  24.2 MBytes   203 Mbits/sec
[  4]   3.00-4.00   sec  0.00 Bytes  0.00 bits/sec
[  4]   4.00-5.00   sec  0.00 Bytes  0.00 bits/sec
^C[  4]   5.00-5.53   sec  0.00 Bytes  0.00 bits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-5.53   sec  0.00 Bytes  0.00 bits/sec                  sender
[  4]   0.00-5.53   sec   189 MBytes   287 Mbits/sec                  receiver
iperf3: interrupt - the client has terminated

These works for hours without this patch applied.

Neil

> 
> Thanks and Best Regards,
> Jose Miguel Abreu
> ---
>  drivers/net/ethernet/stmicro/stmmac/common.h      |   4 +-
>  drivers/net/ethernet/stmicro/stmmac/stmmac.h      |   6 +-
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 207 ++++++++++++++--------
>  3 files changed, 135 insertions(+), 82 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
> index 1854f270ad66..b1b305f8f414 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/common.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/common.h
> @@ -258,10 +258,10 @@ struct stmmac_safety_stats {
>  #define MAX_DMA_RIWT		0xff
>  #define MIN_DMA_RIWT		0x20
>  /* Tx coalesce parameters */
> -#define STMMAC_COAL_TX_TIMER	40000
> +#define STMMAC_COAL_TX_TIMER	1000
>  #define STMMAC_MAX_COAL_TX_TICK	100000
>  #define STMMAC_TX_MAX_FRAMES	256
> -#define STMMAC_TX_FRAMES	64
> +#define STMMAC_TX_FRAMES	25
>  
>  /* Packets types */
>  enum packets_types {
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> index c0a855b7ab3b..957030cfb833 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> @@ -48,6 +48,9 @@ struct stmmac_tx_info {
>  
>  /* Frequently used values are kept adjacent for cache effect */
>  struct stmmac_tx_queue {
> +	u32 tx_count_frames;
> +	int tx_timer_active;
> +	struct timer_list txtimer;
>  	u32 queue_index;
>  	struct stmmac_priv *priv_data;
>  	struct dma_extended_desc *dma_etx ____cacheline_aligned_in_smp;
> @@ -59,6 +62,7 @@ struct stmmac_tx_queue {
>  	dma_addr_t dma_tx_phy;
>  	u32 tx_tail_addr;
>  	u32 mss;
> +	struct napi_struct napi ____cacheline_aligned_in_smp;
>  };
>  
>  struct stmmac_rx_queue {
> @@ -109,14 +113,12 @@ struct stmmac_pps_cfg {
>  
>  struct stmmac_priv {
>  	/* Frequently used values are kept adjacent for cache effect */
> -	u32 tx_count_frames;
>  	u32 tx_coal_frames;
>  	u32 tx_coal_timer;
>  
>  	int tx_coalesce;
>  	int hwts_tx_en;
>  	bool tx_path_in_lpi_mode;
> -	struct timer_list txtimer;
>  	bool tso;
>  
>  	unsigned int dma_buf_sz;
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 9f458bb16f2a..9809c2b319fe 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -148,6 +148,7 @@ static void stmmac_verify_args(void)
>  static void stmmac_disable_all_queues(struct stmmac_priv *priv)
>  {
>  	u32 rx_queues_cnt = priv->plat->rx_queues_to_use;
> +	u32 tx_queues_cnt = priv->plat->tx_queues_to_use;
>  	u32 queue;
>  
>  	for (queue = 0; queue < rx_queues_cnt; queue++) {
> @@ -155,6 +156,12 @@ static void stmmac_disable_all_queues(struct stmmac_priv *priv)
>  
>  		napi_disable(&rx_q->napi);
>  	}
> +
> +	for (queue = 0; queue < tx_queues_cnt; queue++) {
> +		struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue];
> +
> +		napi_disable(&tx_q->napi);
> +	}
>  }
>  
>  /**
> @@ -164,6 +171,7 @@ static void stmmac_disable_all_queues(struct stmmac_priv *priv)
>  static void stmmac_enable_all_queues(struct stmmac_priv *priv)
>  {
>  	u32 rx_queues_cnt = priv->plat->rx_queues_to_use;
> +	u32 tx_queues_cnt = priv->plat->tx_queues_to_use;
>  	u32 queue;
>  
>  	for (queue = 0; queue < rx_queues_cnt; queue++) {
> @@ -171,6 +179,12 @@ static void stmmac_enable_all_queues(struct stmmac_priv *priv)
>  
>  		napi_enable(&rx_q->napi);
>  	}
> +
> +	for (queue = 0; queue < tx_queues_cnt; queue++) {
> +		struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue];
> +
> +		napi_enable(&tx_q->napi);
> +	}
>  }
>  
>  /**
> @@ -1843,7 +1857,8 @@ static void stmmac_dma_operation_mode(struct stmmac_priv *priv)
>   * @queue: TX queue index
>   * Description: it reclaims the transmit resources after transmission completes.
>   */
> -static void stmmac_tx_clean(struct stmmac_priv *priv, u32 queue)
> +static int stmmac_tx_clean(struct stmmac_priv *priv, int limit, u32 queue,
> +			   bool *more)
>  {
>  	struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue];
>  	unsigned int bytes_compl = 0, pkts_compl = 0;
> @@ -1851,10 +1866,13 @@ static void stmmac_tx_clean(struct stmmac_priv *priv, u32 queue)
>  
>  	netif_tx_lock(priv->dev);
>  
> +	if (more)
> +		*more = false;
> +
>  	priv->xstats.tx_clean++;
>  
>  	entry = tx_q->dirty_tx;
> -	while (entry != tx_q->cur_tx) {
> +	while ((entry != tx_q->cur_tx) && (pkts_compl < limit)) {
>  		struct sk_buff *skb = tx_q->tx_skbuff[entry];
>  		struct dma_desc *p;
>  		int status;
> @@ -1937,7 +1955,13 @@ static void stmmac_tx_clean(struct stmmac_priv *priv, u32 queue)
>  		stmmac_enable_eee_mode(priv);
>  		mod_timer(&priv->eee_ctrl_timer, STMMAC_LPI_T(eee_timer));
>  	}
> +
> +	if (more && (tx_q->dirty_tx != tx_q->cur_tx))
> +		*more = true;
> +
>  	netif_tx_unlock(priv->dev);
> +
> +	return pkts_compl;
>  }
>  
>  /**
> @@ -2020,6 +2044,34 @@ static bool stmmac_safety_feat_interrupt(struct stmmac_priv *priv)
>  	return false;
>  }
>  
> +static int stmmac_napi_check(struct stmmac_priv *priv, u32 chan)
> +{
> +	int status = stmmac_dma_interrupt_status(priv, priv->ioaddr,
> +						 &priv->xstats, chan);
> +
> +	if ((status & handle_rx) && (chan < priv->plat->rx_queues_to_use)) {
> +		struct stmmac_rx_queue *rx_q = &priv->rx_queue[chan];
> +
> +		if (likely(napi_schedule_prep(&rx_q->napi))) {
> +			stmmac_disable_dma_irq(priv, priv->ioaddr, chan);
> +			__napi_schedule(&rx_q->napi);
> +		}
> +	} else {
> +		status &= ~handle_rx;
> +	}
> +
> +	if ((status & handle_tx) && (chan < priv->plat->tx_queues_to_use)) {
> +		struct stmmac_tx_queue *tx_q = &priv->tx_queue[chan];
> +
> +		if (likely(napi_schedule_prep(&tx_q->napi)))
> +			__napi_schedule(&tx_q->napi);
> +	} else {
> +		status &= ~handle_tx;
> +	}
> +
> +	return status;
> +}
> +
>  /**
>   * stmmac_dma_interrupt - DMA ISR
>   * @priv: driver private structure
> @@ -2034,57 +2086,14 @@ static void stmmac_dma_interrupt(struct stmmac_priv *priv)
>  	u32 channels_to_check = tx_channel_count > rx_channel_count ?
>  				tx_channel_count : rx_channel_count;
>  	u32 chan;
> -	bool poll_scheduled = false;
>  	int status[max_t(u32, MTL_MAX_TX_QUEUES, MTL_MAX_RX_QUEUES)];
>  
>  	/* Make sure we never check beyond our status buffer. */
>  	if (WARN_ON_ONCE(channels_to_check > ARRAY_SIZE(status)))
>  		channels_to_check = ARRAY_SIZE(status);
>  
> -	/* Each DMA channel can be used for rx and tx simultaneously, yet
> -	 * napi_struct is embedded in struct stmmac_rx_queue rather than in a
> -	 * stmmac_channel struct.
> -	 * Because of this, stmmac_poll currently checks (and possibly wakes)
> -	 * all tx queues rather than just a single tx queue.
> -	 */
>  	for (chan = 0; chan < channels_to_check; chan++)
> -		status[chan] = stmmac_dma_interrupt_status(priv, priv->ioaddr,
> -				&priv->xstats, chan);
> -
> -	for (chan = 0; chan < rx_channel_count; chan++) {
> -		if (likely(status[chan] & handle_rx)) {
> -			struct stmmac_rx_queue *rx_q = &priv->rx_queue[chan];
> -
> -			if (likely(napi_schedule_prep(&rx_q->napi))) {
> -				stmmac_disable_dma_irq(priv, priv->ioaddr, chan);
> -				__napi_schedule(&rx_q->napi);
> -				poll_scheduled = true;
> -			}
> -		}
> -	}
> -
> -	/* If we scheduled poll, we already know that tx queues will be checked.
> -	 * If we didn't schedule poll, see if any DMA channel (used by tx) has a
> -	 * completed transmission, if so, call stmmac_poll (once).
> -	 */
> -	if (!poll_scheduled) {
> -		for (chan = 0; chan < tx_channel_count; chan++) {
> -			if (status[chan] & handle_tx) {
> -				/* It doesn't matter what rx queue we choose
> -				 * here. We use 0 since it always exists.
> -				 */
> -				struct stmmac_rx_queue *rx_q =
> -					&priv->rx_queue[0];
> -
> -				if (likely(napi_schedule_prep(&rx_q->napi))) {
> -					stmmac_disable_dma_irq(priv,
> -							priv->ioaddr, chan);
> -					__napi_schedule(&rx_q->napi);
> -				}
> -				break;
> -			}
> -		}
> -	}
> +		status[chan] = stmmac_napi_check(priv, chan);
>  
>  	for (chan = 0; chan < tx_channel_count; chan++) {
>  		if (unlikely(status[chan] & tx_hard_error_bump_tc)) {
> @@ -2241,13 +2250,11 @@ static int stmmac_init_dma_engine(struct stmmac_priv *priv)
>   */
>  static void stmmac_tx_timer(struct timer_list *t)
>  {
> -	struct stmmac_priv *priv = from_timer(priv, t, txtimer);
> -	u32 tx_queues_count = priv->plat->tx_queues_to_use;
> -	u32 queue;
> +	struct stmmac_tx_queue *tx_q = from_timer(tx_q, t, txtimer);
>  
> -	/* let's scan all the tx queues */
> -	for (queue = 0; queue < tx_queues_count; queue++)
> -		stmmac_tx_clean(priv, queue);
> +	if (likely(napi_schedule_prep(&tx_q->napi)))
> +		__napi_schedule(&tx_q->napi);
> +	tx_q->tx_timer_active = 0;
>  }
>  
>  /**
> @@ -2260,11 +2267,17 @@ static void stmmac_tx_timer(struct timer_list *t)
>   */
>  static void stmmac_init_tx_coalesce(struct stmmac_priv *priv)
>  {
> +	u32 tx_channel_count = priv->plat->tx_queues_to_use;
> +	u32 chan;
> +
>  	priv->tx_coal_frames = STMMAC_TX_FRAMES;
>  	priv->tx_coal_timer = STMMAC_COAL_TX_TIMER;
> -	timer_setup(&priv->txtimer, stmmac_tx_timer, 0);
> -	priv->txtimer.expires = STMMAC_COAL_TIMER(priv->tx_coal_timer);
> -	add_timer(&priv->txtimer);
> +
> +	for (chan = 0; chan < tx_channel_count; chan++) {
> +		struct stmmac_tx_queue *tx_q = &priv->tx_queue[chan];
> +
> +		timer_setup(&tx_q->txtimer, stmmac_tx_timer, 0);
> +	}
>  }
>  
>  static void stmmac_set_rings_length(struct stmmac_priv *priv)
> @@ -2592,6 +2605,7 @@ static void stmmac_hw_teardown(struct net_device *dev)
>  static int stmmac_open(struct net_device *dev)
>  {
>  	struct stmmac_priv *priv = netdev_priv(dev);
> +	u32 chan;
>  	int ret;
>  
>  	stmmac_check_ether_addr(priv);
> @@ -2688,7 +2702,9 @@ static int stmmac_open(struct net_device *dev)
>  	if (dev->phydev)
>  		phy_stop(dev->phydev);
>  
> -	del_timer_sync(&priv->txtimer);
> +	for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++)
> +		del_timer_sync(&priv->tx_queue[chan].txtimer);
> +
>  	stmmac_hw_teardown(dev);
>  init_error:
>  	free_dma_desc_resources(priv);
> @@ -2708,6 +2724,7 @@ static int stmmac_open(struct net_device *dev)
>  static int stmmac_release(struct net_device *dev)
>  {
>  	struct stmmac_priv *priv = netdev_priv(dev);
> +	u32 chan;
>  
>  	if (priv->eee_enabled)
>  		del_timer_sync(&priv->eee_ctrl_timer);
> @@ -2722,7 +2739,8 @@ static int stmmac_release(struct net_device *dev)
>  
>  	stmmac_disable_all_queues(priv);
>  
> -	del_timer_sync(&priv->txtimer);
> +	for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++)
> +		del_timer_sync(&priv->tx_queue[chan].txtimer);
>  
>  	/* Free the IRQ lines */
>  	free_irq(dev->irq, dev);
> @@ -2936,14 +2954,11 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
>  	priv->xstats.tx_tso_nfrags += nfrags;
>  
>  	/* Manage tx mitigation */
> -	priv->tx_count_frames += nfrags + 1;
> -	if (likely(priv->tx_coal_frames > priv->tx_count_frames)) {
> -		mod_timer(&priv->txtimer,
> -			  STMMAC_COAL_TIMER(priv->tx_coal_timer));
> -	} else {
> -		priv->tx_count_frames = 0;
> +	tx_q->tx_count_frames += nfrags + 1;
> +	if (priv->tx_coal_frames <= tx_q->tx_count_frames) {
>  		stmmac_set_tx_ic(priv, desc);
>  		priv->xstats.tx_set_ic_bit++;
> +		tx_q->tx_count_frames = 0;
>  	}
>  
>  	skb_tx_timestamp(skb);
> @@ -2994,6 +3009,12 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
>  
>  	stmmac_set_tx_tail_ptr(priv, priv->ioaddr, tx_q->tx_tail_addr, queue);
>  
> +	if (priv->tx_coal_timer && !tx_q->tx_timer_active) {
> +		tx_q->tx_timer_active = 1;
> +		mod_timer(&tx_q->txtimer,
> +				STMMAC_COAL_TIMER(priv->tx_coal_timer));
> +	}
> +
>  	return NETDEV_TX_OK;
>  
>  dma_map_err:
> @@ -3146,14 +3167,11 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
>  	 * This approach takes care about the fragments: desc is the first
>  	 * element in case of no SG.
>  	 */
> -	priv->tx_count_frames += nfrags + 1;
> -	if (likely(priv->tx_coal_frames > priv->tx_count_frames)) {
> -		mod_timer(&priv->txtimer,
> -			  STMMAC_COAL_TIMER(priv->tx_coal_timer));
> -	} else {
> -		priv->tx_count_frames = 0;
> +	tx_q->tx_count_frames += nfrags + 1;
> +	if (priv->tx_coal_frames <= tx_q->tx_count_frames) {
>  		stmmac_set_tx_ic(priv, desc);
>  		priv->xstats.tx_set_ic_bit++;
> +		tx_q->tx_count_frames = 0;
>  	}
>  
>  	skb_tx_timestamp(skb);
> @@ -3199,8 +3217,15 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
>  	netdev_tx_sent_queue(netdev_get_tx_queue(dev, queue), skb->len);
>  
>  	stmmac_enable_dma_transmission(priv, priv->ioaddr);
> +
>  	stmmac_set_tx_tail_ptr(priv, priv->ioaddr, tx_q->tx_tail_addr, queue);
>  
> +	if (priv->tx_coal_timer && !tx_q->tx_timer_active) {
> +		tx_q->tx_timer_active = 1;
> +		mod_timer(&tx_q->txtimer,
> +				STMMAC_COAL_TIMER(priv->tx_coal_timer));
> +	}
> +
>  	return NETDEV_TX_OK;
>  
>  dma_map_err:
> @@ -3514,27 +3539,41 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)
>   *  Description :
>   *  To look at the incoming frames and clear the tx resources.
>   */
> -static int stmmac_poll(struct napi_struct *napi, int budget)
> +static int stmmac_rx_poll(struct napi_struct *napi, int budget)
>  {
>  	struct stmmac_rx_queue *rx_q =
>  		container_of(napi, struct stmmac_rx_queue, napi);
>  	struct stmmac_priv *priv = rx_q->priv_data;
> -	u32 tx_count = priv->plat->tx_queues_to_use;
>  	u32 chan = rx_q->queue_index;
>  	int work_done = 0;
> -	u32 queue;
>  
>  	priv->xstats.napi_poll++;
>  
> -	/* check all the queues */
> -	for (queue = 0; queue < tx_count; queue++)
> -		stmmac_tx_clean(priv, queue);
> -
>  	work_done = stmmac_rx(priv, budget, rx_q->queue_index);
> +	if (work_done < budget && napi_complete_done(napi, work_done))
> +		stmmac_enable_dma_irq(priv, priv->ioaddr, chan);
> +
> +	return work_done;
> +}
> +
> +static int stmmac_tx_poll(struct napi_struct *napi, int budget)
> +{
> +	struct stmmac_tx_queue *tx_q =
> +		container_of(napi, struct stmmac_tx_queue, napi);
> +	struct stmmac_priv *priv = tx_q->priv_data;
> +	u32 chan = tx_q->queue_index;
> +	int work_done = 0;
> +	bool more;
> +
> +	priv->xstats.napi_poll++;
> +
> +	work_done = stmmac_tx_clean(priv, budget, chan, &more);
>  	if (work_done < budget) {
>  		napi_complete_done(napi, work_done);
> -		stmmac_enable_dma_irq(priv, priv->ioaddr, chan);
> +		if (more)
> +			napi_reschedule(napi);
>  	}
> +
>  	return work_done;
>  }
>  
> @@ -4325,10 +4364,17 @@ int stmmac_dvr_probe(struct device *device,
>  	for (queue = 0; queue < priv->plat->rx_queues_to_use; queue++) {
>  		struct stmmac_rx_queue *rx_q = &priv->rx_queue[queue];
>  
> -		netif_napi_add(ndev, &rx_q->napi, stmmac_poll,
> +		netif_napi_add(ndev, &rx_q->napi, stmmac_rx_poll,
>  			       (8 * priv->plat->rx_queues_to_use));
>  	}
>  
> +	for (queue = 0; queue < priv->plat->tx_queues_to_use; queue++) {
> +		struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue];
> +
> +		netif_napi_add(ndev, &tx_q->napi, stmmac_tx_poll,
> +			       (8 * priv->plat->tx_queues_to_use));
> +	}
> +
>  	mutex_init(&priv->lock);
>  
>  	/* If a specific clk_csr value is passed from the platform
> @@ -4377,6 +4423,11 @@ int stmmac_dvr_probe(struct device *device,
>  
>  		netif_napi_del(&rx_q->napi);
>  	}
> +	for (queue = 0; queue < priv->plat->tx_queues_to_use; queue++) {
> +		struct stmmac_tx_queue *tx_q = &priv->tx_queue[queue];
> +
> +		netif_napi_del(&tx_q->napi);
> +	}
>  error_hw_init:
>  	destroy_workqueue(priv->wq);
>  error_wq:
>