Subject: Re: [PATCH v3 3/4] net: nb8800: Move HW init to ndo_open()

From: Måns Rullgård <[email-masked]>
Date: Tue, 14 Nov 2017 12:40:14 +0000

Marc Gonzalez <[email-masked]> writes:

> Power entire ethernet block down in ndo_stop().
> Power it back up in ndo_open() and perform HW init.
> Delete nb8800_dma_stop.

Leave it alone, please.  Not all chips might have a separate power
domain for this.  Also, it works just fine on the older chips.

> Signed-off-by: Marc Gonzalez <[email-masked]>
> ---
>  drivers/net/ethernet/aurora/nb8800.c | 146 +++++++++--------------------------
>  drivers/net/ethernet/aurora/nb8800.h |   4 +-
>  2 files changed, 40 insertions(+), 110 deletions(-)
>
> diff --git a/drivers/net/ethernet/aurora/nb8800.c b/drivers/net/ethernet/aurora/nb8800.c
> index 09b8001e1ecc..b71d8fb80610 100644
> --- a/drivers/net/ethernet/aurora/nb8800.c
> +++ b/drivers/net/ethernet/aurora/nb8800.c
> @@ -40,7 +40,7 @@
>  #include "nb8800.h"
>
>  static void nb8800_tx_done(struct net_device *dev);
> -static int nb8800_dma_stop(struct net_device *dev);
> +static void nb8800_hw_init(struct net_device *dev);
>
>  static inline u8 nb8800_readb(struct nb8800_priv *priv, int reg)
>  {
> @@ -862,61 +862,6 @@ static int nb8800_dma_init(struct net_device *dev)
>  	return -ENOMEM;
>  }
>
> -static int nb8800_dma_stop(struct net_device *dev)
> -{
> -	struct nb8800_priv *priv = netdev_priv(dev);
> -	struct nb8800_tx_buf *txb = &priv->tx_bufs[0];
> -	struct nb8800_tx_desc *txd = &priv->tx_descs[0];
> -	int retry = 5;
> -	u32 txcr;
> -	u32 rxcr;
> -	int err;
> -	unsigned int i;
> -
> -	/* wait for tx to finish */
> -	err = readl_poll_timeout_atomic(priv->base + NB8800_TXC_CR, txcr,
> -					!(txcr & TCR_EN) &&
> -					priv->tx_done == priv->tx_next,
> -					1000, 1000000);
> -	if (err)
> -		return err;
> -
> -	/* The rx DMA only stops if it reaches the end of chain.
> -	 * To make this happen, we set the EOC flag on all rx
> -	 * descriptors, put the device in loopback mode, and send
> -	 * a few dummy frames.  The interrupt handler will ignore
> -	 * these since NAPI is disabled and no real frames are in
> -	 * the tx queue.
> -	 */
> -
> -	for (i = 0; i < RX_DESC_COUNT; i++)
> -		priv->rx_descs[i].desc.config |= DESC_EOC;
> -
> -	txd->desc[0].s_addr =
> -		txb->dma_desc + offsetof(struct nb8800_tx_desc, buf);
> -	txd->desc[0].config = DESC_BTS(2) | DESC_DS | DESC_EOF | DESC_EOC | 8;
> -	memset(txd->buf, 0, sizeof(txd->buf));
> -
> -	nb8800_mac_af(dev, false);
> -	nb8800_setb(priv, NB8800_MAC_MODE, LOOPBACK_EN);
> -
> -	do {
> -		nb8800_writel(priv, NB8800_TX_DESC_ADDR, txb->dma_desc);
> -		wmb();
> -		nb8800_writel(priv, NB8800_TXC_CR, txcr | TCR_EN);
> -
> -		err = readl_poll_timeout_atomic(priv->base + NB8800_RXC_CR,
> -						rxcr, !(rxcr & RCR_EN),
> -						1000, 100000);
> -	} while (err && --retry);
> -
> -	nb8800_mac_af(dev, true);
> -	nb8800_clearb(priv, NB8800_MAC_MODE, LOOPBACK_EN);
> -	nb8800_dma_reset(dev);
> -
> -	return retry ? 0 : -ETIMEDOUT;
> -}
> -
>  static void nb8800_pause_adv(struct net_device *dev)
>  {
>  	struct nb8800_priv *priv = netdev_priv(dev);
> @@ -941,6 +886,11 @@ static int nb8800_open(struct net_device *dev)
>  	struct phy_device *phydev;
>  	int err;
>
> +	priv->ops->power_up(dev);
> +	nb8800_hw_init(dev);
> +	priv->ops->init(dev);
> +	nb8800_update_mac_addr(dev);
> +
>  	/* clear any pending interrupts */
>  	nb8800_writel(priv, NB8800_RXC_SR, 0xf);
>  	nb8800_writel(priv, NB8800_TXC_SR, 0xf);
> @@ -993,12 +943,11 @@ static int nb8800_stop(struct net_device *dev)
>  	netif_stop_queue(dev);
>  	napi_disable(&priv->napi);
>
> -	nb8800_dma_stop(dev);
> -	nb8800_mac_rx(dev, false);
> -	nb8800_mac_tx(dev, false);
> -
>  	phy_disconnect(phydev);
>
> +	priv->ops->power_down(dev);
> +	priv->speed = 0;
> +
>  	free_irq(dev->irq, dev);
>
>  	nb8800_dma_free(dev);
> @@ -1150,7 +1099,7 @@ static const struct ethtool_ops nb8800_ethtool_ops = {
>  	.set_link_ksettings	= phy_ethtool_set_link_ksettings,
>  };
>
> -static int nb8800_hw_init(struct net_device *dev)
> +static void nb8800_hw_init(struct net_device *dev)
>  {
>  	struct nb8800_priv *priv = netdev_priv(dev);
>  	u32 val;
> @@ -1230,20 +1179,14 @@ static int nb8800_hw_init(struct net_device *dev)
>  	nb8800_writeb(priv, NB8800_PQ1, val >> 8);
>  	nb8800_writeb(priv, NB8800_PQ2, val & 0xff);
>
> -	/* Auto-negotiate by default */
> -	priv->pause_aneg = true;
> -	priv->pause_rx = true;
> -	priv->pause_tx = true;
> -
>  	nb8800_mc_init(dev, 0);
> -
> -	return 0;
>  }
>
>  static int nb8800_tangox_init(struct net_device *dev)
>  {
>  	struct nb8800_priv *priv = netdev_priv(dev);
>  	u32 pad_mode = PAD_MODE_MII;
> +	int clk_div;
>
>  	switch (priv->phy_mode) {
>  	case PHY_INTERFACE_MODE_MII:
> @@ -1266,29 +1209,26 @@ static int nb8800_tangox_init(struct net_device *dev)
>
>  	nb8800_writeb(priv, NB8800_TANGOX_PAD_MODE, pad_mode);
>
> +	clk_div = DIV_ROUND_UP(clk_get_rate(priv->clk), 2 * MAX_MDC_CLOCK);
> +	nb8800_writew(priv, NB8800_TANGOX_MDIO_CLKDIV, clk_div);
> +
>  	return 0;
>  }
>
> -static int nb8800_tangox_reset(struct net_device *dev)
> +static void nb8800_tango_power_down(struct net_device *dev)
>  {
> -	struct nb8800_priv *priv = netdev_priv(dev);
> -	int clk_div;
> -
> -	nb8800_writeb(priv, NB8800_TANGOX_RESET, 0);
> -	usleep_range(1000, 10000);
> -	nb8800_writeb(priv, NB8800_TANGOX_RESET, 1);
> -
> -	wmb();		/* ensure reset is cleared before proceeding */
> -
> -	clk_div = DIV_ROUND_UP(clk_get_rate(priv->clk), 2 * MAX_MDC_CLOCK);
> -	nb8800_writew(priv, NB8800_TANGOX_MDIO_CLKDIV, clk_div);
> +	nb8800_writel(netdev_priv(dev), NB8800_TANGOX_RESET, 0);
> +}
>
> -	return 0;
> +static void nb8800_tango_power_up(struct net_device *dev)
> +{
> +	nb8800_writel(netdev_priv(dev), NB8800_TANGOX_RESET, 1);
>  }
>
>  static const struct nb8800_ops nb8800_tangox_ops = {
> -	.init	= nb8800_tangox_init,
> -	.reset	= nb8800_tangox_reset,
> +	.init		= nb8800_tangox_init,
> +	.power_down	= nb8800_tango_power_down,
> +	.power_up	= nb8800_tango_power_up,
>  };
>
>  static int nb8800_tango4_init(struct net_device *dev)
> @@ -1314,8 +1254,9 @@ static int nb8800_tango4_init(struct net_device *dev)
>  }
>
>  static const struct nb8800_ops nb8800_tango4_ops = {
> -	.init	= nb8800_tango4_init,
> -	.reset	= nb8800_tangox_reset,
> +	.init		= nb8800_tango4_init,
> +	.power_down	= nb8800_tango_power_down,
> +	.power_up	= nb8800_tango_power_up,
>  };
>
>  static const struct of_device_id nb8800_dt_ids[] = {
> @@ -1334,7 +1275,6 @@ MODULE_DEVICE_TABLE(of, nb8800_dt_ids);
>  static int nb8800_probe(struct platform_device *pdev)
>  {
>  	const struct of_device_id *match;
> -	const struct nb8800_ops *ops = NULL;
>  	struct nb8800_priv *priv;
>  	struct resource *res;
>  	struct net_device *dev;
> @@ -1345,8 +1285,8 @@ static int nb8800_probe(struct platform_device *pdev)
>  	int ret;
>
>  	match = of_match_device(nb8800_dt_ids, &pdev->dev);
> -	if (match)
> -		ops = match->data;
> +	if (!match || !match->data)
> +		return -ENODEV;
>
>  	irq = platform_get_irq(pdev, 0);
>  	if (irq <= 0) {
> @@ -1388,12 +1328,6 @@ static int nb8800_probe(struct platform_device *pdev)
>
>  	spin_lock_init(&priv->tx_lock);
>
> -	if (ops && ops->reset) {
> -		ret = ops->reset(dev);
> -		if (ret)
> -			goto err_disable_clk;
> -	}
> -
>  	bus = devm_mdiobus_alloc(&pdev->dev);
>  	if (!bus) {
>  		ret = -ENOMEM;
> @@ -1435,16 +1369,6 @@ static int nb8800_probe(struct platform_device *pdev)
>
>  	priv->mii_bus = bus;
>
> -	ret = nb8800_hw_init(dev);
> -	if (ret)
> -		goto err_deregister_fixed_link;
> -
> -	if (ops && ops->init) {
> -		ret = ops->init(dev);
> -		if (ret)
> -			goto err_deregister_fixed_link;
> -	}
> -
>  	dev->netdev_ops = &nb8800_netdev_ops;
>  	dev->ethtool_ops = &nb8800_ethtool_ops;
>  	dev->flags |= IFF_MULTICAST;
> @@ -1457,24 +1381,28 @@ static int nb8800_probe(struct platform_device *pdev)
>  	if (!is_valid_ether_addr(dev->dev_addr))
>  		eth_hw_addr_random(dev);
>
> -	nb8800_update_mac_addr(dev);
> -
>  	netif_carrier_off(dev);
>
>  	ret = register_netdev(dev);
>  	if (ret) {
>  		netdev_err(dev, "failed to register netdev\n");
> -		goto err_free_dma;
> +		goto err_deregister_fixed_link;
>  	}
>
>  	netif_napi_add(dev, &priv->napi, nb8800_poll, NAPI_POLL_WEIGHT);
>
>  	netdev_info(dev, "MAC address %pM\n", dev->dev_addr);
>
> +	/* Auto-negotiate by default */
> +	priv->pause_aneg = true;
> +	priv->pause_rx = true;
> +	priv->pause_tx = true;
> +
> +	priv->ops = match->data;
> +	priv->ops->power_down(dev);
> +
>  	return 0;
>
> -err_free_dma:
> -	nb8800_dma_free(dev);
>  err_deregister_fixed_link:
>  	if (of_phy_is_fixed_link(pdev->dev.of_node))
>  		of_phy_deregister_fixed_link(pdev->dev.of_node);
> diff --git a/drivers/net/ethernet/aurora/nb8800.h b/drivers/net/ethernet/aurora/nb8800.h
> index 6ec4a956e1e5..23fefca54804 100644
> --- a/drivers/net/ethernet/aurora/nb8800.h
> +++ b/drivers/net/ethernet/aurora/nb8800.h
> @@ -305,11 +305,13 @@ struct nb8800_priv {
>  	dma_addr_t			tx_desc_dma;
>
>  	struct clk			*clk;
> +	const struct nb8800_ops		*ops;
>  };
>
>  struct nb8800_ops {
>  	int				(*init)(struct net_device *dev);
> -	int				(*reset)(struct net_device *dev);
> +	void				(*power_down)(struct net_device *dev);
> +	void				(*power_up)(struct net_device *dev);
>  };
>
>  #endif /* _NB8800_H_ */
> -- 
> 2.15.0
>

-- 
Måns Rullgård