[PATCH] dz.c: Don't panic() when request_irq() fails

["Maciej W. Rozycki" <macro@xxxxxxxxxxxxxx>]

 Well, panic() is a little bit undue if request_irq() fails; there is 
probably no need to justify it any further.  Handle the case gracefully, 
by unregistering the driver.

Signed-off-by: Maciej W. Rozycki <macro@xxxxxxxxxxxxxx>
---
 Tested with checkpatch.pl and at the run-time -- MIPS/Linux on a
DECstation 5000/200.

 Please apply,

  Maciej

patch-mips-2.6.18-20060920-dz-init-0
diff -up --recursive --new-file linux-mips-2.6.18-20060920.macro/drivers/serial/dz.c linux-mips-2.6.18-20060920/drivers/serial/dz.c
--- linux-mips-2.6.18-20060920.macro/drivers/serial/dz.c	2006-11-23 05:17:01.000000000 +0000
+++ linux-mips-2.6.18-20060920/drivers/serial/dz.c	2007-01-14 00:39:20.000000000 +0000
@@ -795,18 +795,28 @@ static int __init dz_init(void)
 	dz_reset(&dz_ports[0]);
 #endif
 
-	if (request_irq(dz_ports[0].port.irq, dz_interrupt,
-			IRQF_DISABLED, "DZ", &dz_ports[0]))
-		panic("Unable to register DZ interrupt");
-
 	ret = uart_register_driver(&dz_reg);
 	if (ret != 0)
-		return ret;
+		goto out;
+
+	ret = request_irq(dz_ports[0].port.irq, dz_interrupt, IRQF_DISABLED,
+			  "DZ", &dz_ports[0]);
+	if (ret != 0) {
+		printk(KERN_ERR "dz: Cannot get IRQ %d!\n",
+		       dz_ports[0].port.irq);
+		goto out_unregister;
+	}
 
 	for (i = 0; i < DZ_NB_PORT; i++)
 		uart_add_one_port(&dz_reg, &dz_ports[i].port);
 
 	return ret;
+
+out_unregister:
+	uart_unregister_driver(&dz_reg);
+
+out:
+	return ret;
 }
 
 module_init(dz_init);