1 files changed, 65 insertions, 31 deletions

diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
index 7addf2fd55de..ccd6566a515e 100644
--- a/drivers/media/video/v4l2-dev.c
+++ b/drivers/media/video/v4l2-dev.c
@@ -65,6 +65,7 @@ static struct device_attribute video_device_attrs[] = {
  */
 static struct video_device *video_device[VIDEO_NUM_DEVICES];
 static DEFINE_MUTEX(videodev_lock);
+static DECLARE_BITMAP(video_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES);
 
 struct video_device *video_device_alloc(void)
 {
@@ -99,6 +100,7 @@ static void v4l2_chardev_release(struct kobject *kobj)
 
         /* Free up this device for reuse */
         video_device[vfd->minor] = NULL;
+        clear_bit(vfd->num, video_nums[vfd->vfl_type]);
         mutex_unlock(&videodev_lock);
 
         /* Release the character device */
@@ -217,10 +219,10 @@ int video_register_device_index(struct video_device *vfd, int type, int nr,
                                         int index)
 {
         int i = 0;
-        int base;
-        int end;
         int ret;
-        char *name_base;
+        int minor_offset = 0;
+        int minor_cnt = VIDEO_NUM_DEVICES;
+        const char *name_base;
         void *priv = video_get_drvdata(vfd);
 
         /* the release callback MUST be present */
@@ -231,23 +233,15 @@ int video_register_device_index(struct video_device *vfd, int type, int nr,
 
         switch (type) {
         case VFL_TYPE_GRABBER:
-                base = MINOR_VFL_TYPE_GRABBER_MIN;
-                end = MINOR_VFL_TYPE_GRABBER_MAX+1;
                 name_base = "video";
                 break;
         case VFL_TYPE_VTX:
-                base = MINOR_VFL_TYPE_VTX_MIN;
-                end = MINOR_VFL_TYPE_VTX_MAX+1;
                 name_base = "vtx";
                 break;
         case VFL_TYPE_VBI:
-                base = MINOR_VFL_TYPE_VBI_MIN;
-                end = MINOR_VFL_TYPE_VBI_MAX+1;
                 name_base = "vbi";
                 break;
         case VFL_TYPE_RADIO:
-                base = MINOR_VFL_TYPE_RADIO_MIN;
-                end = MINOR_VFL_TYPE_RADIO_MAX+1;
                 name_base = "radio";
                 break;
         default:
@@ -256,31 +250,70 @@ int video_register_device_index(struct video_device *vfd, int type, int nr,
                 return -EINVAL;
         }
 
+        vfd->vfl_type = type;
+
+#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
+        /* Keep the ranges for the first four types for historical
+         * reasons.
+         * Newer devices (not yet in place) should use the range
+         * of 128-191 and just pick the first free minor there
+         * (new style). */
+        switch (type) {
+        case VFL_TYPE_GRABBER:
+                minor_offset = 0;
+                minor_cnt = 64;
+                break;
+        case VFL_TYPE_RADIO:
+                minor_offset = 64;
+                minor_cnt = 64;
+                break;
+        case VFL_TYPE_VTX:
+                minor_offset = 192;
+                minor_cnt = 32;
+                break;
+        case VFL_TYPE_VBI:
+                minor_offset = 224;
+                minor_cnt = 32;
+                break;
+        default:
+                minor_offset = 128;
+                minor_cnt = 64;
+                break;
+        }
+#endif
+
         /* Initialize the character device */
         cdev_init(&vfd->cdev, vfd->fops);
         vfd->cdev.owner = vfd->fops->owner;
         /* pick a minor number */
         mutex_lock(&videodev_lock);
-        if (nr >= 0 && nr < end-base) {
-                /* use the one the driver asked for */
-                i = base + nr;
-                if (NULL != video_device[i]) {
-                        mutex_unlock(&videodev_lock);
-                        return -ENFILE;
-                }
-        } else {
-                /* use first free */
-                for (i = base; i < end; i++)
-                        if (NULL == video_device[i])
-                                break;
-                if (i == end) {
-                        mutex_unlock(&videodev_lock);
-                        return -ENFILE;
-                }
+        nr = find_next_zero_bit(video_nums[type], minor_cnt, nr == -1 ? 0 : nr);
+        if (nr == minor_cnt)
+                nr = find_first_zero_bit(video_nums[type], minor_cnt);
+        if (nr == minor_cnt) {
+                printk(KERN_ERR "could not get a free kernel number\n");
+                mutex_unlock(&videodev_lock);
+                return -ENFILE;
         }
-        video_device[i] = vfd;
-        vfd->vfl_type = type;
-        vfd->minor = i;
+#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
+        /* 1-on-1 mapping of kernel number to minor number */
+        i = nr;
+#else
+        /* The kernel number and minor numbers are independent */
+        for (i = 0; i < VIDEO_NUM_DEVICES; i++)
+                if (video_device[i] == NULL)
+                        break;
+        if (i == VIDEO_NUM_DEVICES) {
+                mutex_unlock(&videodev_lock);
+                printk(KERN_ERR "could not get a free minor\n");
+                return -ENFILE;
+        }
+#endif
+        vfd->minor = i + minor_offset;
+        vfd->num = nr;
+        set_bit(nr, video_nums[type]);
+        BUG_ON(video_device[vfd->minor]);
+        video_device[vfd->minor] = vfd;
 
         ret = get_index(vfd, index);
         vfd->index = ret;
@@ -306,7 +339,7 @@ int video_register_device_index(struct video_device *vfd, int type, int nr,
         vfd->dev.devt = MKDEV(VIDEO_MAJOR, vfd->minor);
         if (vfd->parent)
                 vfd->dev.parent = vfd->parent;
-        sprintf(vfd->dev.bus_id, "%s%d", name_base, i - base);
+        sprintf(vfd->dev.bus_id, "%s%d", name_base, nr);
         ret = device_register(&vfd->dev);
         if (ret < 0) {
                 printk(KERN_ERR "%s: device_register failed\n", __func__);
@@ -324,6 +357,7 @@ del_cdev:
 fail_minor:
         mutex_lock(&videodev_lock);
         video_device[vfd->minor] = NULL;
+        clear_bit(vfd->num, video_nums[type]);
         mutex_unlock(&videodev_lock);
         vfd->minor = -1;
         return ret;