[PATCH 3.16 241/245] [media] media-devnode: fix namespace mess

Ben Hutchings
2020-04-23T23:08:44Z

From: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

commit 163f1e93e995048b894c5fc86a6034d16beed740 upstream.

Along all media controller code, "mdev" is used to represent
a pointer to struct media_device, and "devnode" for a pointer
to struct media_devnode.

However, inside media-devnode.[ch], "mdev" is used to represent
a pointer to struct media_devnode.

This is very confusing and may lead to development errors.

So, let's change all occurrences at media-devnode.[ch] to
also use "devnode" for such pointers.

This patch doesn't make any functional changes.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
[bwh: Backported to 3.16: adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/media/media-devnode.c | 110 +++++++++++++++++-----------------
include/media/media-devnode.h | 16 ++---
2 files changed, 63 insertions(+), 63 deletions(-)

--- a/drivers/media/media-devnode.c
+++ b/drivers/media/media-devnode.c
@@ -59,21 +59,21 @@ static DECLARE_BITMAP(media_devnode_nums
/* Called when the last user of the media device exits. */
static void media_devnode_release(struct device *cd)
{
- struct media_devnode *mdev = to_media_devnode(cd);
+ struct media_devnode *devnode = to_media_devnode(cd);

mutex_lock(&media_devnode_lock);

/* Delete the cdev on this minor as well */
- cdev_del(&mdev->cdev);
+ cdev_del(&devnode->cdev);

/* Mark device node number as free */
- clear_bit(mdev->minor, media_devnode_nums);
+ clear_bit(devnode->minor, media_devnode_nums);

mutex_unlock(&media_devnode_lock);

/* Release media_devnode and perform other cleanups as needed. */
- if (mdev->release)
- mdev->release(mdev);
+ if (devnode->release)
+ devnode->release(devnode);
}

static struct bus_type media_bus_type = {
@@ -83,37 +83,37 @@ static struct bus_type media_bus_type =
static ssize_t media_read(struct file *filp, char __user *buf,
size_t sz, loff_t *off)
{
- struct media_devnode *mdev = media_devnode_data(filp);
+ struct media_devnode *devnode = media_devnode_data(filp);

- if (!mdev->fops->read)
+ if (!devnode->fops->read)
return -EINVAL;
- if (!media_devnode_is_registered(mdev))
+ if (!media_devnode_is_registered(devnode))
return -EIO;
- return mdev->fops->read(filp, buf, sz, off);
+ return devnode->fops->read(filp, buf, sz, off);
}

static ssize_t media_write(struct file *filp, const char __user *buf,
size_t sz, loff_t *off)
{
- struct media_devnode *mdev = media_devnode_data(filp);
+ struct media_devnode *devnode = media_devnode_data(filp);

- if (!mdev->fops->write)
+ if (!devnode->fops->write)
return -EINVAL;
- if (!media_devnode_is_registered(mdev))
+ if (!media_devnode_is_registered(devnode))
return -EIO;
- return mdev->fops->write(filp, buf, sz, off);
+ return devnode->fops->write(filp, buf, sz, off);
}

static unsigned int media_poll(struct file *filp,
struct poll_table_struct *poll)
{
- struct media_devnode *mdev = media_devnode_data(filp);
+ struct media_devnode *devnode = media_devnode_data(filp);

- if (!media_devnode_is_registered(mdev))
+ if (!media_devnode_is_registered(devnode))
return POLLERR | POLLHUP;
- if (!mdev->fops->poll)
+ if (!devnode->fops->poll)
return DEFAULT_POLLMASK;
- return mdev->fops->poll(filp, poll);
+ return devnode->fops->poll(filp, poll);
}

static long
@@ -121,12 +121,12 @@ __media_ioctl(struct file *filp, unsigne
long (*ioctl_func)(struct file *filp, unsigned int cmd,
unsigned long arg))
{
- struct media_devnode *mdev = media_devnode_data(filp);
+ struct media_devnode *devnode = media_devnode_data(filp);

if (!ioctl_func)
return -ENOTTY;

- if (!media_devnode_is_registered(mdev))
+ if (!media_devnode_is_registered(devnode))
return -EIO;

return ioctl_func(filp, cmd, arg);
@@ -134,9 +134,9 @@ __media_ioctl(struct file *filp, unsigne

static long media_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
- struct media_devnode *mdev = media_devnode_data(filp);
+ struct media_devnode *devnode = media_devnode_data(filp);

- return __media_ioctl(filp, cmd, arg, mdev->fops->ioctl);
+ return __media_ioctl(filp, cmd, arg, devnode->fops->ioctl);
}

#ifdef CONFIG_COMPAT
@@ -144,9 +144,9 @@ static long media_ioctl(struct file *fil
static long media_compat_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg)
{
- struct media_devnode *mdev = media_devnode_data(filp);
+ struct media_devnode *devnode = media_devnode_data(filp);

- return __media_ioctl(filp, cmd, arg, mdev->fops->compat_ioctl);
+ return __media_ioctl(filp, cmd, arg, devnode->fops->compat_ioctl);
}

#endif /* CONFIG_COMPAT */
@@ -154,7 +154,7 @@ static long media_compat_ioctl(struct fi
/* Override for the open function */
static int media_open(struct inode *inode, struct file *filp)
{
- struct media_devnode *mdev;
+ struct media_devnode *devnode;
int ret;

/* Check if the media device is available. This needs to be done with
@@ -164,23 +164,23 @@ static int media_open(struct inode *inod
* a crash.
*/
mutex_lock(&media_devnode_lock);
- mdev = container_of(inode->i_cdev, struct media_devnode, cdev);
+ devnode = container_of(inode->i_cdev, struct media_devnode, cdev);
/* return ENXIO if the media device has been removed
already or if it is not registered anymore. */
- if (!media_devnode_is_registered(mdev)) {
+ if (!media_devnode_is_registered(devnode)) {
mutex_unlock(&media_devnode_lock);
return -ENXIO;
}
/* and increase the device refcount */
- get_device(&mdev->dev);
+ get_device(&devnode->dev);
mutex_unlock(&media_devnode_lock);

- filp->private_data = mdev;
+ filp->private_data = devnode;

- if (mdev->fops->open) {
- ret = mdev->fops->open(filp);
+ if (devnode->fops->open) {
+ ret = devnode->fops->open(filp);
if (ret) {
- put_device(&mdev->dev);
+ put_device(&devnode->dev);
filp->private_data = NULL;
return ret;
}
@@ -192,16 +192,16 @@ static int media_open(struct inode *inod
/* Override for the release function */
static int media_release(struct inode *inode, struct file *filp)
{
- struct media_devnode *mdev = media_devnode_data(filp);
+ struct media_devnode *devnode = media_devnode_data(filp);

- if (mdev->fops->release)
- mdev->fops->release(filp);
+ if (devnode->fops->release)
+ devnode->fops->release(filp);

filp->private_data = NULL;

/* decrease the refcount unconditionally since the release()
return value is ignored. */
- put_device(&mdev->dev);
+ put_device(&devnode->dev);
return 0;
}

@@ -221,7 +221,7 @@ static const struct file_operations medi

/**
* media_devnode_register - register a media device node
- * @mdev: media device node structure we want to register
+ * @devnode: media device node structure we want to register
*
* The registration code assigns minor numbers and registers the new device node
* with the kernel. An error is returned if no free minor number can be found,
@@ -233,7 +233,7 @@ static const struct file_operations medi
* the media_devnode structure is *not* called, so the caller is responsible for
* freeing any data.
*/
-int __must_check media_devnode_register(struct media_devnode *mdev,
+int __must_check media_devnode_register(struct media_devnode *devnode,
struct module *owner)
{
int minor;
@@ -251,40 +251,40 @@ int __must_check media_devnode_register(
set_bit(minor, media_devnode_nums);
mutex_unlock(&media_devnode_lock);

- mdev->minor = minor;
+ devnode->minor = minor;

/* Part 2: Initialize and register the character device */
- cdev_init(&mdev->cdev, &media_devnode_fops);
- mdev->cdev.owner = owner;
+ cdev_init(&devnode->cdev, &media_devnode_fops);
+ devnode->cdev.owner = owner;

- ret = cdev_add(&mdev->cdev, MKDEV(MAJOR(media_dev_t), mdev->minor), 1);
+ ret = cdev_add(&devnode->cdev, MKDEV(MAJOR(media_dev_t), devnode->minor), 1);
if (ret < 0) {
pr_err("%s: cdev_add failed\n", __func__);
goto error;
}

/* Part 3: Register the media device */
- mdev->dev.bus = &media_bus_type;
- mdev->dev.devt = MKDEV(MAJOR(media_dev_t), mdev->minor);
- mdev->dev.release = media_devnode_release;
- if (mdev->parent)
- mdev->dev.parent = mdev->parent;
- dev_set_name(&mdev->dev, "media%d", mdev->minor);
- ret = device_register(&mdev->dev);
+ devnode->dev.bus = &media_bus_type;
+ devnode->dev.devt = MKDEV(MAJOR(media_dev_t), devnode->minor);
+ devnode->dev.release = media_devnode_release;
+ if (devnode->parent)
+ devnode->dev.parent = devnode->parent;
+ dev_set_name(&devnode->dev, "media%d", devnode->minor);
+ ret = device_register(&devnode->dev);
if (ret < 0) {
pr_err("%s: device_register failed\n", __func__);
goto error;
}

/* Part 4: Activate this minor. The char device can now be used. */
- set_bit(MEDIA_FLAG_REGISTERED, &mdev->flags);
+ set_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);

return 0;

error:
mutex_lock(&media_devnode_lock);
- cdev_del(&mdev->cdev);
- clear_bit(mdev->minor, media_devnode_nums);
+ cdev_del(&devnode->cdev);
+ clear_bit(devnode->minor, media_devnode_nums);
mutex_unlock(&media_devnode_lock);

return ret;
@@ -292,7 +292,7 @@ error:

/**
* media_devnode_unregister - unregister a media device node
- * @mdev: the device node to unregister
+ * @devnode: the device node to unregister
*
* This unregisters the passed device. Future open calls will be met with
* errors.
@@ -300,16 +300,16 @@ error:
* This function can safely be called if the device node has never been
* registered or has already been unregistered.
*/
-void media_devnode_unregister(struct media_devnode *mdev)
+void media_devnode_unregister(struct media_devnode *devnode)
{
- /* Check if mdev was ever registered at all */
- if (!media_devnode_is_registered(mdev))
+ /* Check if devnode was ever registered at all */
+ if (!media_devnode_is_registered(devnode))
return;

mutex_lock(&media_devnode_lock);
- clear_bit(MEDIA_FLAG_REGISTERED, &mdev->flags);
+ clear_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
mutex_unlock(&media_devnode_lock);
- device_unregister(&mdev->dev);
+ device_unregister(&devnode->dev);
}

/*
--- a/include/media/media-devnode.h
+++ b/include/media/media-devnode.h
@@ -76,24 +76,24 @@ struct media_devnode {
unsigned long flags; /* Use bitops to access flags */

/* callbacks */
- void (*release)(struct media_devnode *mdev);
+ void (*release)(struct media_devnode *devnode);
};

/* dev to media_devnode */
#define to_media_devnode(cd) container_of(cd, struct media_devnode, dev)

-int __must_check media_devnode_register(struct media_devnode *mdev,
+int __must_check media_devnode_register(struct media_devnode *devnode,
struct module *owner);
-void media_devnode_unregister(struct media_devnode *mdev);
+void media_devnode_unregister(struct media_devnode *devnode);

static inline struct media_devnode *media_devnode_data(struct file *filp)
{
return filp->private_data;
}

-static inline int media_devnode_is_registered(struct media_devnode *mdev)
+static inline int media_devnode_is_registered(struct media_devnode *devnode)
{
- return test_bit(MEDIA_FLAG_REGISTERED, &mdev->flags);
+ return test_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
}

#endif /* _MEDIA_DEVNODE_H */