uio: Cleanup irq handling.

Change the value of UIO_IRQ_NONE -2 to 0.  0 is well defined in the rest
of the kernel as the value to indicate an irq has not been assigned.

Update the calls to request_irq and free_irq to only ignore UIO_IRQ_NONE
and UIO_IRQ_CUSTOM allowing the rest of the kernel's possible irq
numbers to be used.

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Hans J. Koch <hjk@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 8 insertions, 8 deletions

diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 8132288920b2..0fd2cda74244 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -512,7 +512,7 @@ static unsigned int uio_poll(struct file *filep, poll_table *wait)
         struct uio_listener *listener = filep->private_data;
         struct uio_device *idev = listener->dev;
 
-        if (idev->info->irq == UIO_IRQ_NONE)
+        if (!idev->info->irq)
                 return -EIO;
 
         poll_wait(filep, &idev->wait, wait);
@@ -530,7 +530,7 @@ static ssize_t uio_read(struct file *filep, char __user *buf,
         ssize_t retval;
         s32 event_count;
 
-        if (idev->info->irq == UIO_IRQ_NONE)
+        if (!idev->info->irq)
                 return -EIO;
 
         if (count != sizeof(s32))
@@ -578,7 +578,7 @@ static ssize_t uio_write(struct file *filep, const char __user *buf,
         ssize_t retval;
         s32 irq_on;
 
-        if (idev->info->irq == UIO_IRQ_NONE)
+        if (!idev->info->irq)
                 return -EIO;
 
         if (count != sizeof(s32))
@@ -825,9 +825,9 @@ int __uio_register_device(struct module *owner,
 
         info->uio_dev = idev;
 
-        if (idev->info->irq >= 0) {
-                ret = request_irq(idev->info->irq, uio_interrupt,
-                                  idev->info->irq_flags, idev->info->name, idev);
+        if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) {
+                ret = request_irq(info->irq, uio_interrupt,
+                                  info->irq_flags, info->name, idev);
                 if (ret)
                         goto err_request_irq;
         }
@@ -863,7 +863,7 @@ void uio_unregister_device(struct uio_info *info)
 
         uio_free_minor(idev);
 
-        if (info->irq >= 0)
+        if (info->irq && (info->irq != UIO_IRQ_CUSTOM))
                 free_irq(info->irq, idev);
 
         uio_dev_del_attributes(idev);
diff --git a/include/linux/uio_driver.h b/include/linux/uio_driver.h
index 5dcc9ff72f69..d6188e5a52df 100644
--- a/include/linux/uio_driver.h
+++ b/include/linux/uio_driver.h
@@ -108,7 +108,7 @@ extern void uio_event_notify(struct uio_info *info);
 
 /* defines for uio_info->irq */
 #define UIO_IRQ_CUSTOM  -1
-#define UIO_IRQ_NONE    -2
+#define UIO_IRQ_NONE    0
 
 /* defines for uio_mem->memtype */
 #define UIO_MEM_NONE    0