Commit 864fdf88 authored by Anton Vorontsov's avatar Anton Vorontsov Committed by David S. Miller
Browse files

ucc_geth: Fix hangs after switching from full to half duplex 



MPC8360 QE UCC ethernet controllers hang when changing link duplex
under a load (a bit of NFS activity is enough).

  PHY: mdio@e0102120:00 - Link is Up - 1000/Full
  sh-3.00# ethtool -s eth0 speed 100 duplex half autoneg off
  PHY: mdio@e0102120:00 - Link is Down
  PHY: mdio@e0102120:00 - Link is Up - 100/Half
  NETDEV WATCHDOG: eth0 (ucc_geth): transmit queue 0 timed out
  ------------[ cut here ]------------
  Badness at c01fcbd0 [verbose debug info unavailable]
  NIP: c01fcbd0 LR: c01fcbd0 CTR: c0194e44
  ...

The cure is to disable the controller before changing speed/duplex
and enable it afterwards.

Though, disabling the controller might take quite a while, so we
better not grab any spinlocks in adjust_link(). Instead, we quiesce
the driver's activity, and only then disable the controller.

Signed-off-by: default avatarAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7de8ee78

drivers/net/ucc_geth.c

+31 −5
Original line number Diff line number Diff line
@@ -1561,6 +1561,25 @@ static int ugeth_disable(struct ucc_geth_private *ugeth, enum comm_dir mode) 
	return 0;

}



static void ugeth_quiesce(struct ucc_geth_private *ugeth)

{

	/* Wait for and prevent any further xmits. */

	netif_tx_disable(ugeth->ndev);



	/* Disable the interrupt to avoid NAPI rescheduling. */

	disable_irq(ugeth->ug_info->uf_info.irq);



	/* Stop NAPI, and possibly wait for its completion. */

	napi_disable(&ugeth->napi);

}



static void ugeth_activate(struct ucc_geth_private *ugeth)

{

	napi_enable(&ugeth->napi);

	enable_irq(ugeth->ug_info->uf_info.irq);

	netif_tx_wake_all_queues(ugeth->ndev);

}



/* 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 ugeth structure, and this
@@ -1574,14 +1593,11 @@ static void adjust_link(struct net_device *dev) 
	struct ucc_geth __iomem *ug_regs;

	struct ucc_fast __iomem *uf_regs;

	struct phy_device *phydev = ugeth->phydev;

	unsigned long flags;

	int new_state = 0;



	ug_regs = ugeth->ug_regs;

	uf_regs = ugeth->uccf->uf_regs;



	spin_lock_irqsave(&ugeth->lock, flags);



	if (phydev->link) {

		u32 tempval = in_be32(&ug_regs->maccfg2);

		u32 upsmr = in_be32(&uf_regs->upsmr);
@@ -1632,9 +1648,21 @@ static void adjust_link(struct net_device *dev) 
			ugeth->oldspeed = phydev->speed;

		}



		/*

		 * To change the MAC configuration we need to disable the

		 * controller. To do so, we have to either grab ugeth->lock,

		 * which is a bad idea since 'graceful stop' commands might

		 * take quite a while, or we can quiesce driver's activity.

		 */

		ugeth_quiesce(ugeth);

		ugeth_disable(ugeth, COMM_DIR_RX_AND_TX);



		out_be32(&ug_regs->maccfg2, tempval);

		out_be32(&uf_regs->upsmr, upsmr);



		ugeth_enable(ugeth, COMM_DIR_RX_AND_TX);

		ugeth_activate(ugeth);



		if (!ugeth->oldlink) {

			new_state = 1;

			ugeth->oldlink = 1;
@@ -1648,8 +1676,6 @@ static void adjust_link(struct net_device *dev) 


	if (new_state && netif_msg_link(ugeth))

		phy_print_status(phydev);



	spin_unlock_irqrestore(&ugeth->lock, flags);

}



/* Initialize TBI PHY interface for communicating with the

CRA Git | Maintained and supported by SUSTech CRA and CCSE