From 864fdf884e82bacbe8ca5e93bd43393a61d2e2b4 Mon Sep 17 00:00:00 2001
From: Anton Vorontsov <avorontsov@ru.mvista.com>
Date: Thu, 10 Sep 2009 11:48:12 +0000
Subject: [PATCH] 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 <avorontsov@ru.mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
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 a39368a46352a..4469f2451a6f6 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
--
2.39.5