[patch 128/149] ucc_geth: Fix netdev watchdog triggering on link changes

Greg KH
2010-07-01T18:30:08Z

2.6.32-stable review patch. If anyone has any objections, please let us know.

------------------

From: Anton Vorontsov <avorontsov@ru.mvista.com>

commit 08b5e1c91ce95793c59a59529a362a1bcc81faae upstream.

Since commit 864fdf884e82bacbe8ca5e93bd43393a61d2e2b4 ("ucc_geth:
Fix hangs after switching from full to half duplex") ucc_geth driver
disables the controller during MAC configuration changes. Though,
disabling the controller might take quite awhile, and so the netdev
watchdog might get upset:

NETDEV WATCHDOG: eth2 (ucc_geth): transmit queue 0 timed out
------------[ cut here ]------------
Badness at c02729a8 [verbose debug info unavailable]
NIP: c02729a8 LR: c02729a8 CTR: c01b6088
REGS: c0451c40 TRAP: 0700 Not tainted (2.6.32-trunk-8360e)
[...]
NIP [c02729a8] dev_watchdog+0x280/0x290
LR [c02729a8] dev_watchdog+0x280/0x290
Call Trace:
[c0451cf0] [c02729a8] dev_watchdog+0x280/0x290 (unreliable)
[c0451d50] [c00377c4] run_timer_softirq+0x164/0x224
[c0451da0] [c0032a38] __do_softirq+0xb8/0x13c
[c0451df0] [c00065cc] do_softirq+0xa0/0xac
[c0451e00] [c003280c] irq_exit+0x7c/0x9c
[c0451e10] [c00640c4] __ipipe_sync_stage+0x248/0x24c
[...]

This patch fixes the issue by detaching the netdev during the
time we change the configuration.

Reported-by: Lennart Sorensen <lsorense@csclub.uwaterloo.ca>
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Tested-by: Lennart Sorensen <lsorense@csclub.uwaterloo.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/net/ucc_geth.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/net/ucc_geth.c
+++ b/drivers/net/ucc_geth.c
@@ -1563,7 +1563,10 @@ static int ugeth_disable(struct ucc_geth

static void ugeth_quiesce(struct ucc_geth_private *ugeth)
{
- /* Wait for and prevent any further xmits. */
+ /* Prevent any further xmits, plus detach the device. */
+ netif_device_detach(ugeth->ndev);
+
+ /* Wait for any current xmits to finish. */
netif_tx_disable(ugeth->ndev);

/* Disable the interrupt to avoid NAPI rescheduling. */
@@ -1577,7 +1580,7 @@ static void ugeth_activate(struct ucc_ge
{
napi_enable(&ugeth->napi);
enable_irq(ugeth->ug_info->uf_info.irq);
- netif_tx_wake_all_queues(ugeth->ndev);
+ netif_device_attach(ugeth->ndev);
}

/* Called every time the controller might need to be made