V4L/DVB (8390): videodev: add comment and remove magic number.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 6 insertions, 2 deletions

diff --git a/drivers/media/video/videodev.c b/drivers/media/video/videodev.c
index bf12b5f850e2..aca36dec6746 100644
--- a/drivers/media/video/videodev.c
+++ b/drivers/media/video/videodev.c
@@ -2023,9 +2023,13 @@ EXPORT_SYMBOL(video_ioctl2);
 static int get_index(struct video_device *vdev, int num)
 {
         u32 used = 0;
+        const unsigned max_index = sizeof(used) * 8 - 1;
         int i;
 
-        if (num >= 32) {
+        /* Currently a single v4l driver instance cannot create more than
+           32 devices.
+           Increase to u64 or an array of u32 if more are needed. */
+        if (num > max_index) {
                 printk(KERN_ERR "videodev: %s num is too large\n", __func__);
                 return -EINVAL;
         }
@@ -2045,7 +2049,7 @@ static int get_index(struct video_device *vdev, int num)
         }
 
         i = ffz(used);
-        return i >= 32 ? -ENFILE : i;
+        return i > max_index ? -ENFILE : i;
 }
 
 static const struct file_operations video_fops;