Bluetooth: Redo checks in IRQ handler for shared IRQ support

Commit ac019360fe changed the irq handler logic to BUG_ON rather than
returning IRQ_NONE when the incoming argument is invalid.  While this
works in most cases, it doesn't work when the IRQ is shared with other
devices (or when DEBUG_SHIRQ is enabled).

So revert the previous change and replace the warning message with a
comment explaining that we want this behavior.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/bluecard_cs.c

@@ -503,7 +503,9 @@ static irqreturn_t bluecard_interrupt(int irq, void *dev_inst)
 	unsigned int iobase;
 	unsigned char reg;
 
-	BUG_ON(!info->hdev);
+	if (!info || !info->hdev)
+		/* our irq handler is shared */
+		return IRQ_NONE;
 
 	if (!test_bit(CARD_READY, &(info->hw_state)))
 		return IRQ_HANDLED;

drivers/bluetooth/bt3c_cs.c

@@ -345,7 +345,9 @@ static irqreturn_t bt3c_interrupt(int irq, void *dev_inst)
 	int iir;
 	irqreturn_t r = IRQ_NONE;
 
-	BUG_ON(!info->hdev);
+	if (!info || !info->hdev)
+		/* our irq handler is shared */
+		return IRQ_NONE;
 
 	iobase = info->p_dev->io.BasePort1;
 

drivers/bluetooth/btuart_cs.c

@@ -295,7 +295,9 @@ static irqreturn_t btuart_interrupt(int irq, void *dev_inst)
 	int iir, lsr;
 	irqreturn_t r = IRQ_NONE;
 
-	BUG_ON(!info->hdev);
+	if (!info || !info->hdev)
+		/* our irq handler is shared */
+		return IRQ_NONE;
 
 	iobase = info->p_dev->io.BasePort1;
 

drivers/bluetooth/dtl1_cs.c

@@ -299,7 +299,9 @@ static irqreturn_t dtl1_interrupt(int irq, void *dev_inst)
 	int iir, lsr;
 	irqreturn_t r = IRQ_NONE;
 
-	BUG_ON(!info->hdev);
+	if (!info || !info->hdev)
+		/* our irq handler is shared */
+		return IRQ_NONE;
 
 	iobase = info->p_dev->io.BasePort1;