sungem: Soft lockup in sungem on Netra AC200 when switching interface up
From: Ilkka Virta <itvirta@iki.fi>
In the lockup situation the driver seems to go off in an eternal storm
of interrupts right after calling request_irq(). It doesn't actually
do anything interesting in the interrupt handler. Since connecting the link
afterwards works, something later in initialization must fix this.
Looking at gem_do_start() and gem_open(), it seems that the only thing
done while opening the device after the request_irq(), is a call to
napi_enable().
I don't know what the ordering requirements are for the
initialization, but I boldly tried to move the napi_enable() call
inside gem_do_start() before the link state is checked and interrupts
subsequently enabled, and it seems to work for me. Doesn't even break
anything too obvious...
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/sungem.c b/drivers/net/sungem.c
index b17efa9..4918763 100644
--- a/drivers/net/sungem.c
+++ b/drivers/net/sungem.c
@@ -2221,6 +2221,8 @@
gp->running = 1;
+ napi_enable(&gp->napi);
+
if (gp->lstate == link_up) {
netif_carrier_on(gp->dev);
gem_set_link_modes(gp);
@@ -2238,6 +2240,8 @@
spin_lock_irqsave(&gp->lock, flags);
spin_lock(&gp->tx_lock);
+ napi_disable(&gp->napi);
+
gp->running = 0;
gem_reset(gp);
gem_clean_rings(gp);
@@ -2338,8 +2342,6 @@
if (!gp->asleep)
rc = gem_do_start(dev);
gp->opened = (rc == 0);
- if (gp->opened)
- napi_enable(&gp->napi);
mutex_unlock(&gp->pm_mutex);
@@ -2476,8 +2478,6 @@
/* Re-attach net device */
netif_device_attach(dev);
-
- napi_enable(&gp->napi);
}
spin_lock_irqsave(&gp->lock, flags);