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Commit 775a05dd authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab
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V4L/DVB (10641): v4l2-dev: remove limit of 32 devices per driver in get_index() 



get_index() had a limitation of 32 devices per driver. This was
unnecessarily strict and has been replaced with the maximum number
of devices. That should really satisfy anyone!

Signed-off-by: default avatarHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 27d35fc3

drivers/media/video/v4l2-dev.c

+13 −12
Original line number Diff line number Diff line
@@ -288,37 +288,38 @@ static const struct file_operations v4l2_fops = { 
 */

static int get_index(struct video_device *vdev, int num)

{

	u32 used = 0;

	const int max_index = sizeof(used) * 8 - 1;

	/* This can be static since this function is called with the global

	   videodev_lock held. */

	static DECLARE_BITMAP(used, VIDEO_NUM_DEVICES);

	int i;



	/* 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) {

	if (num >= VIDEO_NUM_DEVICES) {

		printk(KERN_ERR "videodev: %s num is too large\n", __func__);

		return -EINVAL;

	}



	/* Some drivers do not set the parent. In that case always return 0. */

	/* Some drivers do not set the parent. In that case always return

	   num or 0. */

	if (vdev->parent == NULL)

		return 0;

		return num >= 0 ? num : 0;



	bitmap_zero(used, VIDEO_NUM_DEVICES);



	for (i = 0; i < VIDEO_NUM_DEVICES; i++) {

		if (video_device[i] != NULL &&

		    video_device[i]->parent == vdev->parent) {

			used |= 1 << video_device[i]->index;

			set_bit(video_device[i]->index, used);

		}

	}



	if (num >= 0) {

		if (used & (1 << num))

		if (test_bit(num, used))

			return -ENFILE;

		return num;

	}



	i = ffz(used);

	return i > max_index ? -ENFILE : i;

	i = find_first_zero_bit(used, VIDEO_NUM_DEVICES);

	return i == VIDEO_NUM_DEVICES ? -ENFILE : i;

}



int video_register_device(struct video_device *vdev, int type, int nr)