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Commit 5cf6f7f3 authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab
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[media] v4l2-core: remove the old .ioctl BKL replacement 



To keep V4L2 drivers that did not yet convert to unlocked_ioctl happy,
the v4l2 core had a .ioctl file operation that took a V4L2 lock.

The last drivers are now converted to unlocked_ioctl, so all this
old code can now be removed.

Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@osg.samsung.com>
parent 06e5cc3d

drivers/media/v4l2-core/v4l2-dev.c

+0 −28
Original line number Diff line number Diff line
@@ -357,34 +357,6 @@ static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 
			ret = vdev->fops->unlocked_ioctl(filp, cmd, arg);

		if (lock)

			mutex_unlock(lock);

	} else if (vdev->fops->ioctl) {

		/* This code path is a replacement for the BKL. It is a major

		 * hack but it will have to do for those drivers that are not

		 * yet converted to use unlocked_ioctl.

		 *

		 * All drivers implement struct v4l2_device, so we use the

		 * lock defined there to serialize the ioctls.

		 *

		 * However, if the driver sleeps, then it blocks all ioctls

		 * since the lock is still held. This is very common for

		 * VIDIOC_DQBUF since that normally waits for a frame to arrive.

		 * As a result any other ioctl calls will proceed very, very

		 * slowly since each call will have to wait for the VIDIOC_QBUF

		 * to finish. Things that should take 0.01s may now take 10-20

		 * seconds.

		 *

		 * The workaround is to *not* take the lock for VIDIOC_DQBUF.

		 * This actually works OK for videobuf-based drivers, since

		 * videobuf will take its own internal lock.

		 */

		struct mutex *m = &vdev->v4l2_dev->ioctl_lock;



		if (cmd != VIDIOC_DQBUF && mutex_lock_interruptible(m))

			return -ERESTARTSYS;

		if (video_is_registered(vdev))

			ret = vdev->fops->ioctl(filp, cmd, arg);

		if (cmd != VIDIOC_DQBUF)

			mutex_unlock(m);

	} else

		ret = -ENOTTY;

drivers/media/v4l2-core/v4l2-device.c

+0 −1
Original line number Diff line number Diff line
@@ -37,7 +37,6 @@ int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev) 


	INIT_LIST_HEAD(&v4l2_dev->subdevs);

	spin_lock_init(&v4l2_dev->lock);

	mutex_init(&v4l2_dev->ioctl_lock);

	v4l2_prio_init(&v4l2_dev->prio);

	kref_init(&v4l2_dev->ref);

	get_device(dev);

include/media/v4l2-dev.h

+0 −1
Original line number Diff line number Diff line
@@ -65,7 +65,6 @@ struct v4l2_file_operations { 
	ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);

	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);

	unsigned int (*poll) (struct file *, struct poll_table_struct *);

	long (*ioctl) (struct file *, unsigned int, unsigned long);

	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);

#ifdef CONFIG_COMPAT

	long (*compat_ioctl32) (struct file *, unsigned int, unsigned long);

include/media/v4l2-device.h

+0 −2
Original line number Diff line number Diff line
@@ -58,8 +58,6 @@ struct v4l2_device { 
	struct v4l2_ctrl_handler *ctrl_handler;

	/* Device's priority state */

	struct v4l2_prio_state prio;

	/* BKL replacement mutex. Temporary solution only. */

	struct mutex ioctl_lock;

	/* Keep track of the references to this struct. */

	struct kref ref;

	/* Release function that is called when the ref count goes to 0. */