Hi Ingo,

RT driver patch to eliminate in_atomic stack dump.

The problem code was identified by Michael S. Tsirkin, and he suggested
the fix.

I adapted to use RT's _nort primitives- should work correctly in all
configs.

Thanks,

Sven


Fixes in_atomic stack-dump, when Mellanox module 
is loaded into the RT Kernel.

From: Michael S. Tsirkin <redacted> 

"Basically, if you just make spin_lock_irqsave (and spin_lock_irq) not disable
interrupts for non-raw spinlocks, I think all of infiniband will be fine without
changes."

signed-off-by: Sven-Thorsten Dietrich <redacted>


Index: linux-2.6.21/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
===================================================================

--- linux-2.6.21.orig/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ linux-2.6.21/drivers/infiniband/ulp/ipoib/ipoib_multicast.c

@@ -788,7 +788,7 @@ void ipoib_mcast_restart_task(struct wor
 
 	ipoib_mcast_stop_thread(dev, 0);
 
-	local_irq_save(flags);
+	local_irq_save_nort(flags);
 	netif_tx_lock(dev);
 	spin_lock(&priv->lock);
 

@@ -863,7 +863,7 @@ void ipoib_mcast_restart_task(struct wor
 
 	spin_unlock(&priv->lock);
 	netif_tx_unlock(dev);
-	local_irq_restore(flags);
+	local_irq_restore_nort(flags);
 
 	/* We have to cancel outside of the spinlock */
 	list_for_each_entry_safe(mcast, tmcast, &remove_list, list) {