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Commit 75e80683 authored by Stephen Hemminger's avatar Stephen Hemminger Committed by Jeff Garzik
Browse files

sky2: receive FIFO checking 



A driver writer from another operating system hinted that
the versions of Yukon 2 chip with rambuffer (EC and XL) have
a hardware bug that if the FIFO ever gets completely full it
will hang. Sounds like a classic ring full vs ring empty wrap around
bug.

As a workaround, use the existing watchdog timer to check for
ring full lockup.

Signed-off-by: default avatarStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent 05745c4a

drivers/net/sky2.c

+58 −16
Original line number Diff line number Diff line
@@ -1648,9 +1648,6 @@ static int sky2_down(struct net_device *dev) 
	if (netif_msg_ifdown(sky2))

		printk(KERN_INFO PFX "%s: disabling interface\n", dev->name);



	if (netif_carrier_ok(dev) && --hw->active == 0)

		del_timer(&hw->watchdog_timer);



	/* Stop more packets from being queued */

	netif_stop_queue(dev);
@@ -1775,10 +1772,8 @@ static void sky2_link_up(struct sky2_port *sky2) 


	netif_carrier_on(sky2->netdev);



	if (hw->active++ == 0)

	mod_timer(&hw->watchdog_timer, jiffies + 1);





	/* Turn on link LED */

	sky2_write8(hw, SK_REG(port, LNK_LED_REG),

		    LINKLED_ON | LINKLED_BLINK_OFF | LINKLED_LINKSYNC_OFF);
@@ -1828,11 +1823,6 @@ static void sky2_link_down(struct sky2_port *sky2) 


	netif_carrier_off(sky2->netdev);



	/* Stop watchdog if both ports are not active */

	if (--hw->active == 0)

		del_timer(&hw->watchdog_timer);





	/* Turn on link LED */

	sky2_write8(hw, SK_REG(port, LNK_LED_REG), LINKLED_OFF);
@@ -2484,19 +2474,71 @@ static void sky2_le_error(struct sky2_hw *hw, unsigned port, 
	sky2_write32(hw, Q_ADDR(q, Q_CSR), BMU_CLR_IRQ_CHK);

}



/* Check for lost IRQ once a second */

static int sky2_rx_hung(struct net_device *dev)

{

	struct sky2_port *sky2 = netdev_priv(dev);

	struct sky2_hw *hw = sky2->hw;

	unsigned port = sky2->port;

	unsigned rxq = rxqaddr[port];

	u32 mac_rp = sky2_read32(hw, SK_REG(port, RX_GMF_RP));

	u8 mac_lev = sky2_read8(hw, SK_REG(port, RX_GMF_RLEV));

	u8 fifo_rp = sky2_read8(hw, Q_ADDR(rxq, Q_RP));

	u8 fifo_lev = sky2_read8(hw, Q_ADDR(rxq, Q_RL));



	/* If idle and MAC or PCI is stuck */

	if (sky2->check.last == dev->last_rx &&

	    ((mac_rp == sky2->check.mac_rp &&

	      mac_lev != 0 && mac_lev >= sky2->check.mac_lev) ||

	     /* Check if the PCI RX hang */

	     (fifo_rp == sky2->check.fifo_rp &&

	      fifo_lev != 0 && fifo_lev >= sky2->check.fifo_lev))) {

		printk(KERN_DEBUG PFX "%s: hung mac %d:%d fifo %d (%d:%d)\n",

		       dev->name, mac_lev, mac_rp, fifo_lev, fifo_rp,

		       sky2_read8(hw, Q_ADDR(rxq, Q_WP)));

		return 1;

	} else {

		sky2->check.last = dev->last_rx;

		sky2->check.mac_rp = mac_rp;

		sky2->check.mac_lev = mac_lev;

		sky2->check.fifo_rp = fifo_rp;

		sky2->check.fifo_lev = fifo_lev;

		return 0;

	}

}



static void sky2_watchdog(unsigned long arg)

{

	struct sky2_hw *hw = (struct sky2_hw *) arg;

	struct net_device *dev;



	/* Check for lost IRQ once a second */

	if (sky2_read32(hw, B0_ISRC)) {

		struct net_device *dev = hw->dev[0];



		dev = hw->dev[0];

		if (__netif_rx_schedule_prep(dev))

			__netif_rx_schedule(dev);

	} else {

		int i, active = 0;



		for (i = 0; i < hw->ports; i++) {

			dev = hw->dev[i];

			if (!netif_running(dev))

				continue;

			++active;



			/* For chips with Rx FIFO, check if stuck */

			if ((hw->flags & SKY2_HW_RAMBUFFER) &&

			     sky2_rx_hung(dev)) {

				pr_info(PFX "%s: receiver hang detected\n",

					dev->name);

				schedule_work(&hw->restart_work);

				return;

			}

		}



		if (active == 0)

			return;

	}



	if (hw->active > 0)

	mod_timer(&hw->watchdog_timer, round_jiffies(jiffies + HZ));

}

drivers/net/sky2.h

+8 −1
Original line number Diff line number Diff line
@@ -2027,6 +2027,14 @@ struct sky2_port { 
	u16		     rx_tag;

	struct vlan_group    *vlgrp;

#endif

	struct {

		unsigned long last;

		u32	mac_rp;

		u8	mac_lev;

		u8	fifo_rp;

		u8	fifo_lev;

	} check;





	dma_addr_t	     rx_le_map;

	dma_addr_t	     tx_le_map;
@@ -2064,7 +2072,6 @@ struct sky2_hw { 
	u8		     chip_rev;

	u8		     pmd_type;

	u8		     ports;

	u8		     active;



	struct sky2_status_le *st_le;

	u32		     st_idx;