Commit 6ce29b0e authored by Claudiu Manoil's avatar Claudiu Manoil Committed by David S. Miller
Browse files

gianfar: Avoid unnecessary reg accesses in adjust_link() 



For phy devices that don't issue interrupts upon link
state changes, phylib polls the link state resulting in
repeated calls to adjust_link(), even if the link state
didn't change.  As a result, some mac registers are
repeatedly read and written with the same values, which
is not ok.

To fix this, adjust_link() has been refactored to check
first whether the link state has changed and to take action
only if needed, updating mac registers and local state
variables.  The 'new_state' local flag, set if one of the
link params changed (link, speed or duplex), has been
rendered useless and removed by this refactoring.

Signed-off-by: default avatarClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0cda345d

drivers/net/ethernet/freescale/gianfar.c

+113 −110
Original line number Diff line number Diff line
@@ -121,6 +121,7 @@ static irqreturn_t gfar_error(int irq, void *dev_id); 
static irqreturn_t gfar_transmit(int irq, void *dev_id);

static irqreturn_t gfar_interrupt(int irq, void *dev_id);

static void adjust_link(struct net_device *dev);

static noinline void gfar_update_link_state(struct gfar_private *priv);

static int init_phy(struct net_device *dev);

static int gfar_probe(struct platform_device *ofdev);

static int gfar_remove(struct platform_device *ofdev);
@@ -3076,41 +3077,6 @@ static irqreturn_t gfar_interrupt(int irq, void *grp_id) 
	return IRQ_HANDLED;

}



static u32 gfar_get_flowctrl_cfg(struct gfar_private *priv)

{

	struct phy_device *phydev = priv->phydev;

	u32 val = 0;



	if (!phydev->duplex)

		return val;



	if (!priv->pause_aneg_en) {

		if (priv->tx_pause_en)

			val |= MACCFG1_TX_FLOW;

		if (priv->rx_pause_en)

			val |= MACCFG1_RX_FLOW;

	} else {

		u16 lcl_adv, rmt_adv;

		u8 flowctrl;

		/* get link partner capabilities */

		rmt_adv = 0;

		if (phydev->pause)

			rmt_adv = LPA_PAUSE_CAP;

		if (phydev->asym_pause)

			rmt_adv |= LPA_PAUSE_ASYM;



		lcl_adv = mii_advertise_flowctrl(phydev->advertising);



		flowctrl = mii_resolve_flowctrl_fdx(lcl_adv, rmt_adv);

		if (flowctrl & FLOW_CTRL_TX)

			val |= MACCFG1_TX_FLOW;

		if (flowctrl & FLOW_CTRL_RX)

			val |= MACCFG1_RX_FLOW;

	}



	return val;

}



/* Called every time the controller might need to be made

 * aware of new link state.  The PHY code conveys this

 * information through variables in the phydev structure, and this
@@ -3120,83 +3086,12 @@ static u32 gfar_get_flowctrl_cfg(struct gfar_private *priv) 
static void adjust_link(struct net_device *dev)

{

	struct gfar_private *priv = netdev_priv(dev);

	struct gfar __iomem *regs = priv->gfargrp[0].regs;

	struct phy_device *phydev = priv->phydev;

	int new_state = 0;



	if (test_bit(GFAR_RESETTING, &priv->state))

		return;



	if (phydev->link) {

		u32 tempval1 = gfar_read(&regs->maccfg1);

		u32 tempval = gfar_read(&regs->maccfg2);

		u32 ecntrl = gfar_read(&regs->ecntrl);



		/* Now we make sure that we can be in full duplex mode.

		 * If not, we operate in half-duplex mode.

		 */

		if (phydev->duplex != priv->oldduplex) {

			new_state = 1;

			if (!(phydev->duplex))

				tempval &= ~(MACCFG2_FULL_DUPLEX);

			else

				tempval |= MACCFG2_FULL_DUPLEX;



			priv->oldduplex = phydev->duplex;

		}



		if (phydev->speed != priv->oldspeed) {

			new_state = 1;

			switch (phydev->speed) {

			case 1000:

				tempval =

				    ((tempval & ~(MACCFG2_IF)) | MACCFG2_GMII);



				ecntrl &= ~(ECNTRL_R100);

				break;

			case 100:

			case 10:

				tempval =

				    ((tempval & ~(MACCFG2_IF)) | MACCFG2_MII);



				/* Reduced mode distinguishes

				 * between 10 and 100

				 */

				if (phydev->speed == SPEED_100)

					ecntrl |= ECNTRL_R100;

				else

					ecntrl &= ~(ECNTRL_R100);

				break;

			default:

				netif_warn(priv, link, dev,

					   "Ack!  Speed (%d) is not 10/100/1000!\n",

					   phydev->speed);

				break;

			}



			priv->oldspeed = phydev->speed;

		}



		tempval1 &= ~(MACCFG1_TX_FLOW | MACCFG1_RX_FLOW);

		tempval1 |= gfar_get_flowctrl_cfg(priv);



		gfar_write(&regs->maccfg1, tempval1);

		gfar_write(&regs->maccfg2, tempval);

		gfar_write(&regs->ecntrl, ecntrl);



		if (!priv->oldlink) {

			new_state = 1;

			priv->oldlink = 1;

		}

	} else if (priv->oldlink) {

		new_state = 1;

		priv->oldlink = 0;

		priv->oldspeed = 0;

		priv->oldduplex = -1;

	}



	if (new_state && netif_msg_link(priv))

		phy_print_status(phydev);

	if (unlikely(phydev->link != priv->oldlink ||

		     phydev->duplex != priv->oldduplex ||

		     phydev->speed != priv->oldspeed))

		gfar_update_link_state(priv);

}



/* Update the hash table based on the current list of multicast
@@ -3442,6 +3337,114 @@ static irqreturn_t gfar_error(int irq, void *grp_id) 
	return IRQ_HANDLED;

}



static u32 gfar_get_flowctrl_cfg(struct gfar_private *priv)

{

	struct phy_device *phydev = priv->phydev;

	u32 val = 0;



	if (!phydev->duplex)

		return val;



	if (!priv->pause_aneg_en) {

		if (priv->tx_pause_en)

			val |= MACCFG1_TX_FLOW;

		if (priv->rx_pause_en)

			val |= MACCFG1_RX_FLOW;

	} else {

		u16 lcl_adv, rmt_adv;

		u8 flowctrl;

		/* get link partner capabilities */

		rmt_adv = 0;

		if (phydev->pause)

			rmt_adv = LPA_PAUSE_CAP;

		if (phydev->asym_pause)

			rmt_adv |= LPA_PAUSE_ASYM;



		lcl_adv = mii_advertise_flowctrl(phydev->advertising);



		flowctrl = mii_resolve_flowctrl_fdx(lcl_adv, rmt_adv);

		if (flowctrl & FLOW_CTRL_TX)

			val |= MACCFG1_TX_FLOW;

		if (flowctrl & FLOW_CTRL_RX)

			val |= MACCFG1_RX_FLOW;

	}



	return val;

}



static noinline void gfar_update_link_state(struct gfar_private *priv)

{

	struct gfar __iomem *regs = priv->gfargrp[0].regs;

	struct phy_device *phydev = priv->phydev;



	if (unlikely(test_bit(GFAR_RESETTING, &priv->state)))

		return;



	if (phydev->link) {

		u32 tempval1 = gfar_read(&regs->maccfg1);

		u32 tempval = gfar_read(&regs->maccfg2);

		u32 ecntrl = gfar_read(&regs->ecntrl);



		if (phydev->duplex != priv->oldduplex) {

			if (!(phydev->duplex))

				tempval &= ~(MACCFG2_FULL_DUPLEX);

			else

				tempval |= MACCFG2_FULL_DUPLEX;



			priv->oldduplex = phydev->duplex;

		}



		if (phydev->speed != priv->oldspeed) {

			switch (phydev->speed) {

			case 1000:

				tempval =

				    ((tempval & ~(MACCFG2_IF)) | MACCFG2_GMII);



				ecntrl &= ~(ECNTRL_R100);

				break;

			case 100:

			case 10:

				tempval =

				    ((tempval & ~(MACCFG2_IF)) | MACCFG2_MII);



				/* Reduced mode distinguishes

				 * between 10 and 100

				 */

				if (phydev->speed == SPEED_100)

					ecntrl |= ECNTRL_R100;

				else

					ecntrl &= ~(ECNTRL_R100);

				break;

			default:

				netif_warn(priv, link, priv->ndev,

					   "Ack!  Speed (%d) is not 10/100/1000!\n",

					   phydev->speed);

				break;

			}



			priv->oldspeed = phydev->speed;

		}



		tempval1 &= ~(MACCFG1_TX_FLOW | MACCFG1_RX_FLOW);

		tempval1 |= gfar_get_flowctrl_cfg(priv);



		gfar_write(&regs->maccfg1, tempval1);

		gfar_write(&regs->maccfg2, tempval);

		gfar_write(&regs->ecntrl, ecntrl);



		if (!priv->oldlink)

			priv->oldlink = 1;



	} else if (priv->oldlink) {

		priv->oldlink = 0;

		priv->oldspeed = 0;

		priv->oldduplex = -1;

	}



	if (netif_msg_link(priv))

		phy_print_status(phydev);

}



static struct of_device_id gfar_match[] =

{

	{

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