Staging: meilhaus: convert nested spin_lock_irqsave to spin_lock

If spin_lock_irqsave is called twice in a row with the same second
argument, the interrupt state at the point of the second call overwrites
the value saved by the first call.  Indeed, the second call does not need
to save the interrupt state, so it is changed to a simple spin_lock.

The semantic match that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
expression lock1,lock2;
expression flags;
@@

*spin_lock_irqsave(lock1,flags)
... when != flags
*spin_lock_irqsave(lock2,flags)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: David Kiliani <mail@davidkiliani.de>
Cc: Meilhaus Support <support@meilhaus.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


diff --git a/drivers/staging/meilhaus/me4600_ai.c b/drivers/staging/meilhaus/me4600_ai.c
index e496d0c..fd9daa9 100644
--- a/drivers/staging/meilhaus/me4600_ai.c
+++ b/drivers/staging/meilhaus/me4600_ai.c
@@ -760,7 +760,7 @@
 	// Mark that StreamConfig is removed.
 	instance->chan_list_len = 0;
 
-	spin_lock_irqsave(instance->ctrl_reg_lock, cpu_flags);
+	spin_lock(instance->ctrl_reg_lock);
 	/// @note Imprtant: Preserve EXT IRQ settings.
 	tmp = inl(instance->ctrl_reg);
 	// Clear FIFOs and dissable interrupts
@@ -824,7 +824,7 @@
 		   instance->ctrl_reg - instance->reg_base,
 		   instance->single_config[channel].ctrl | tmp);
 
-	spin_unlock_irqrestore(instance->ctrl_reg_lock, cpu_flags);
+	spin_unlock(instance->ctrl_reg_lock);
 
 	if (!(instance->single_config[channel].ctrl & ME4600_AI_CTRL_BIT_EX_TRIG)) {	// Software start
 		inl(instance->start_reg);
@@ -877,7 +877,7 @@
 	}
 
 	// Restore settings.
-	spin_lock_irqsave(instance->ctrl_reg_lock, cpu_flags);
+	spin_lock(instance->ctrl_reg_lock);
 	tmp = inl(instance->ctrl_reg);
 	// Clear FIFOs and dissable interrupts.
 	tmp &=
@@ -889,7 +889,7 @@
 	outl(tmp, instance->ctrl_reg);
 	PDEBUG_REG("ctrl_reg outl(0x%lX+0x%lX)=0x%x\n", instance->reg_base,
 		   instance->ctrl_reg - instance->reg_base, tmp);
-	spin_unlock_irqrestore(instance->ctrl_reg_lock, cpu_flags);
+	spin_unlock(instance->ctrl_reg_lock);
 
 	spin_unlock_irqrestore(&instance->subdevice_lock, cpu_flags);
 
@@ -1268,7 +1268,7 @@
 	}
 
 	instance->status = ai_status_none;
-	spin_lock_irqsave(instance->ctrl_reg_lock, cpu_flags);
+	spin_lock(instance->ctrl_reg_lock);
 	// Stop all actions. Block all interrupts. Clear (disable) FIFOs.
 	ctrl =
 	    ME4600_AI_CTRL_BIT_LE_IRQ_RESET | ME4600_AI_CTRL_BIT_HF_IRQ_RESET |
@@ -1290,7 +1290,7 @@
 	outl(tmp | ctrl, instance->ctrl_reg);
 	PDEBUG_REG("ctrl_reg outl(0x%lX+0x%lX)=0x%x\n", instance->reg_base,
 		   instance->ctrl_reg - instance->reg_base, tmp | ctrl);
-	spin_unlock_irqrestore(instance->ctrl_reg_lock, cpu_flags);
+	spin_unlock(instance->ctrl_reg_lock);
 
 	// Write the channel list
 	for (i = 0; i < count; i++) {
@@ -1529,7 +1529,7 @@
 	ctrl |= (ME4600_AI_CTRL_BIT_HF_IRQ | ME4600_AI_CTRL_BIT_SC_IRQ | ME4600_AI_CTRL_BIT_LE_IRQ);	//The last IRQ source (ME4600_AI_CTRL_BIT_LE_IRQ) is unused!
 
 	//Everything is good. Finalize
-	spin_lock_irqsave(instance->ctrl_reg_lock, cpu_flags);
+	spin_lock(instance->ctrl_reg_lock);
 	tmp = inl(instance->ctrl_reg);
 
 	//Preserve EXT IRQ and OFFSET settings. Clean other bits.
@@ -1541,7 +1541,7 @@
 	outl(ctrl | tmp, instance->ctrl_reg);
 	PDEBUG_REG("ctrl_reg outl(0x%lX+0x%lX)=0x%x\n", instance->reg_base,
 		   instance->ctrl_reg - instance->reg_base, ctrl | tmp);
-	spin_unlock_irqrestore(instance->ctrl_reg_lock, cpu_flags);
+	spin_unlock(instance->ctrl_reg_lock);
 
 	//Set the global parameters end exit.
 	instance->chan_list_len = count;