From 864fdf884e82bacbe8ca5e93bd43393a61d2e2b4 Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Thu, 10 Sep 2009 11:48:12 +0000 Subject: [PATCH 1/1] 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: Anton Vorontsov Signed-off-by: David S. Miller --- drivers/net/ucc_geth.c | 36 +++++++++++++++++++++++++++++++----- 1 file changed, 31 insertions(+), 5 deletions(-) diff --git a/drivers/net/ucc_geth.c b/drivers/net/ucc_geth.c index a39368a..4469f24 100644 --- a/drivers/net/ucc_geth.c +++ b/drivers/net/ucc_geth.c @@ -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 -- 1.8.2.3