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[media] v4l2-core: remove the old .ioctl BKL replacement

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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: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
This commit is contained in:
Hans Verkuil 2015-02-17 05:44:09 -03:00 committed by Mauro Carvalho Chehab
parent 06e5cc3d0d
commit 5cf6f7f327
4 changed files with 0 additions and 32 deletions
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28
drivers/media/v4l2-core/v4l2-dev.c
View file

@ -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;

1
drivers/media/v4l2-core/v4l2-device.c
View file

@ -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);

1
include/media/v4l2-dev.h
View file

@ -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);

2
include/media/v4l2-device.h
View file

@ -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. */