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 <>
Signed-off-by: default avatarDavid S. Miller <>
parent 7de8ee78
......@@ -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. */
/* Disable the interrupt to avoid NAPI rescheduling. */
/* Stop NAPI, and possibly wait for its completion. */
static void ugeth_activate(struct ucc_geth_private *ugeth)
/* 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_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);
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))
spin_unlock_irqrestore(&ugeth->lock, flags);
/* Initialize TBI PHY interface for communicating with the
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