dummy-irq: require the user to specify an IRQ number
Make sure that we let the user know that without specifying IRQ#,
dummy-irq driver is useless.
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/misc/dummy-irq.c b/drivers/misc/dummy-irq.c
index 7014167..c37eeed 100644
--- a/drivers/misc/dummy-irq.c
+++ b/drivers/misc/dummy-irq.c
@@ -19,7 +19,7 @@
#include <linux/irq.h>
#include <linux/interrupt.h>
-static int irq;
+static int irq = -1;
static irqreturn_t dummy_interrupt(int irq, void *dev_id)
{
@@ -36,6 +36,10 @@
static int __init dummy_irq_init(void)
{
+ if (irq < 0) {
+ printk(KERN_ERR "dummy-irq: no IRQ given. Use irq=N\n");
+ return -EIO;
+ }
if (request_irq(irq, &dummy_interrupt, IRQF_SHARED, "dummy_irq", &irq)) {
printk(KERN_ERR "dummy-irq: cannot register IRQ %d\n", irq);
return -EIO;