The change in 8280b662 does not cover the case when v4l2_dev is already
NULL, fix that.

With a Kinect sensor, seen as an USB camera using GSPCA in this context,
a NULL pointer dereference BUG can be triggered by just unplugging the
device after the camera driver has been loaded.
Signed-off-by: NAntonio Ospite <ospite@studenti.unina.it>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Drivers that have no v4l2_device release callback might free the
v4l2_device instance in the video_device release callback. Make sure we
don't access the v4l2_device instance after it gets freed.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Entities associated with video device nodes are unregistered in
video_unregister_device(). This destroys the entity even though it can
still be accessed through open video device nodes.

Move the media_device_unregister_entity() call from
video_unregister_device() to v4l2_device_release() to ensure that the
entity isn't unregistered until the last reference to the video device
is released.

Also remove the media_entity_get()/put() calls from v4l2-dev.c. Those
functions were designed for subdevs, to avoid a parent module from being
removed while still accessible through board code. They're not currently
needed for video device nodes, and will oops when a hotpluggable device
is disconnected during streaming, as media_entity_put() called in
v4l2_device_release() tries to access entity->parent->dev->driver which
is set to NULL when the device is disconnected.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NSakari Ailus <sakari.ailus@iki.fi>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

This reverts commit c29fcff3.
Signed-off-by: NBob Liu <lliubbo@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Subdevs already have their own entity, don't register as second one when
registering the subdev device node.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NSakari Ailus <sakari.ailus@maxwell.research.nokia.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Rather than guess which driver supports core priority handling, require drivers
that do to explicitly set the V4L2_FL_USE_FH_PRIO flag in video_device.

Updated the core prio handling accordingly and set the flag in the three
drivers that do.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

The video_device struct has proper ref counting and its release function
will be called when the last user releases it. But no such support was
available for struct v4l2_device. This made it hard to determine when a
USB driver can release the device if it has multiple device nodes.

With one device node it is easy of course, since when the device node is
released, the whole device can be released.

This patch adds refcounting to v4l2_device. When registering device nodes
the v4l2_device refcount will be increased, when releasing device nodes
it will be decreased. The (optional) release function will be called when
the last device node was released.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Integrate the v4l2_prio_state into the core, ready for use.

One struct v4l2_prio_state is added to v4l2_device and a pointer
to a prio state is added to video_device.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

We are going to move priority handling into the v4l2 core. As a consequence
the v4l2_prio helper functions need to be moved into the core videodev
module as well to prevent circular dependencies.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

V4L2 devices are media entities. As such they need to inherit from
(include) the media_entity structure.

When registering/unregistering the device, the media entity is
automatically registered/unregistered. The entity is acquired on device
open and released on device close.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NSakari Ailus <sakari.ailus@iki.fi>
Acked-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Create a device node named subdevX for every registered subdev.

As the device node is registered before the subdev core::s_config
function is called, return -EGAIN on open until initialization
completes.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NVimarsh Zutshi <vimarsh.zutshi@gmail.com>
Acked-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Zeroing video_device.dev causes a memory leak if video_set_drvdata
was called before video_register_device was called. video_set_drvdata
calls dev_set_drvdata which allocates video_device.dev.p.

memsetting this will prevent freeing of that memory.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

The unregister function had a race condition with the v4l2_open
function. Ensure that both functions test and clear the REGISTER
flag from within a critical section.

Thanks to Laurent Pinchart for finding this race.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

The BKL replacement mutex had some serious performance side-effects on
V4L drivers. It is replaced by a better heuristic that works around the
worst of the side-effects.

Read the v4l2-dev.c comments for the whole sorry story. This is a
temporary measure only until we can convert all v4l drivers to use
unlocked_ioctl.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Where reasonable use mutex_lock_interruptible instead of mutex_lock.
Also fix the poll, read and write error codes when called with an unregistered
device (e.g. after a USB device was disconnected). Poll must return
POLLERR|POLLHUP and read/write must return -ENODEV.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

All of the hard problems for BKL removal appear to be solved in the
v4l-dvb/master tree. This removes the BKL from the various open
functions that do not need it, or only use it to protect an
open count.

The zoran driver is nontrivial in this regard, so I introduce
a new mutex that locks both the open/release and the ioctl
functions. Someone with access to the hardware can probably
improve that by using the existing lock in all cases.

Finally, all drivers that still use the locked version of the
ioctl function now get called under a new mutex instead of
the BKL.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Drivers can optionally set a pointer to a mutex in struct video_device.
The core will use that to lock before calling open, read, write, unlocked_ioctl,
poll, mmap or release.

Updated the documentation as well and ensure that v4l2-event knows about the
lock: it will unlock it before doing a blocking wait on an event and relock it
afterwards.

Ensure that the 'video_is_registered' check is done when the lock is held:
a typical disconnect will take the lock as well before unregistering the
device nodes, so to prevent race conditions the video_is_registered check
should also be done with the lock held.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

The get_unmapped_area file operation is unused. Remove.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Until now all fops except release and (unlocked_)ioctl returned an error
after the device node was unregistered. Extend this as well to the ioctl
fops. There is nothing useful that an application can do here and it
complicates the driver code unnecessarily.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Remove the vtx (aka videotext aka teletext) API from the v4l2 core.
This API was scheduled for removal in kernel 2.6.35.

The vtx device nodes have been superseded by vbi device nodes
for many years. No applications exist that use the vtx support.
Of the two i2c drivers that actually support this API the saa5249
has been impossible to use for a year now and no known hardware
that supports this device exists. The saa5246a is theoretically
supported by the old mxb boards, but it never actually worked.

In summary: there is no hardware that can use this API and there
are no applications actually implementing this API.

The vtx support still reserves minors 192-223 and we would really
like to reuse those for upcoming new functionality. In the unlikely
event that new hardware appears that wants to use the functionality
provided by the vtx API, then that functionality should be build
around the sliced VBI API instead.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Add the calls needed to automatically merge subdev controls into a bridge
control handler.

Hook up the control framework in __video_ioctl2 and video_register_device.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

v4l2 implements two separate file operations for drivers that
use locked and unlocked ioctl callbacks. Since we want to remove
the ioctl file operation in favor of the unlocked variant, this
separation no longer seems helpful.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: NHans Verkuil <hverkuil@xs4all.nl>
Cc: John Kacur <jkacur@redhat.com>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>

Since commit b4028437
the 'driver_data' field resides in device's struct device_private
which may be allocated by dev_set_drvdata() if device_private
struct was not allocated previously.

dev_set_drvdata() is used in video_set_drvdata() to set
the driver's private data pointer in v4l2 drivers. Setting
the private data _before_ registering the v4l2 device results
in a memory leak since __video_register_device() also calls
video_set_drvdata(), but after zeroing the device structure.
Thus, the reference to the previously allocated device_private
struct goes lost and a new device_private will be allocated.

All v4l drivers which call video_set_drvdata() _before_
calling video_register_device() are affected. The patch fixes
__video_register_device() to preserve previously allocated
device_private reference.

Caught by kmemleak.
Signed-off-by: NAnatolij Gustschin <agust@denx.de>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

No need to lock when unregistering the device: clear_bit is already an
atomic operation.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

This patch adds a list of v4l2_fh structures to every video_device.
It allows using file handle related information in V4L2. The event interface
is one example of such use.

The use of v4l2_fh is not mandatory for drivers.
Signed-off-by: NSakari Ailus <sakari.ailus@maxwell.research.nokia.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Replace the video_is_unregistered function by a video_is_registered
function. The V4L2_FL_UNREGISTERED flag is replaced by a
V4L2_FL_REGISTERED flag.

This change makes the video_is_registered function return coherent
results when called on an initialize but not yet registered video_device
instance. The function can now be used instead of checking
video_device::minor.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Many drivers access the device number (video_device::v4l2_devnode::num)
in order to print the video device node name. Add and use a helper
function to retrieve the video_device node name.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Warn when the desired device node number is already in use, except when
the new video_register_device_no_warn function is called since in some
use-cases that warning is not relevant.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

There are some subtle differences in the way the devnode numbers are
handled depending on whether the FIXED_MINOR_RANGES config option is
set. Add some simple wrapper functions to handle that correctly.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

The term 'kernel number' is very vague, so replace it with the somewhat more
descriptive term 'device node number'.

In one place the local variable 'nr' was used to create the device node number
of the new device name. This has been replaced with the vdev->num field to
more clearly mark this as being the device node number and not the minor
number.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

video_register_device_index is never actually called, instead the
stream index number is always calculated automatically.

This patch removes this function and simplifies the internal get_index
function since that can now always just return the first free index.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
  It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT

  This will make hardirq.h inclusion cheaper for every PREEMPT=n config
  (which includes allmodconfig/allyesconfig, BTW)
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch allows v4l2_open and v4l2_release functions return 0 if open and
release driver callbacks set to NULL. This will be used in radio
drivers.

--
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NAlexey Klimov <klimov.linux@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Shared memory mappings on nommu machines require a get_unmapped_area
file operation that suggests an address for the mapping. This patch
adds a way for v4l2 drivers to provide this callback.
Signed-off-by: NDaniel Glöckner <dg@emlix.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Normally the parent device of v4l2_device is used as the video device
node's parent. But if it was not set, then use the parent field in the
video_device struct.

This is needed in the cx88 driver, which has one core v4l2_device but
creates multiple pci devices (one each for raw and mpeg video).

So you cannot associate the core v4l2_device with a particular PCI device,
but you can do that for each video_device.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

The videodev module is missing the char-major-81-* alias that would
cause it to be auto-loaded when a device of that type is opened.  This
patch adds the alias.
Signed-off-by: NScott James Remnant <scott@canonical.com>
Signed-off-by: NTim Gardner <tim.gardner@canonical.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

video_register_device_index() checks if it was passed a NULL video_device
pointer (which isn't allowed) _after_ it has already dereferenced it with
video_get_drvdata(vdev).  The checks are clearly pointless and can be
removed, as the function would have crashed before reaching them if vdev
ever was NULL.
Signed-off-by: NTrent Piepho <xyzzy@speakeasy.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

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: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

This rename prevents conflicts with the older compat_ioctl32 module.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>