vivi previously had a very complex queuing system and held spinlocks while
doing copy_to_user, kmalloc, etc.  This caused the driver to easily deadlock
when a multi-threaded application used it and revealed bugs in videobuf too.

This replaces the copy_to_user with memcpy since we were never copying to user
space addresses.  And makes the kmalloc atomic.
Signed-off-by: NBrandon Philips <bphilips@suse.de>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

vivi currently doesn't have the infrastructure to handle being opened more than
one time and will crash if it is.  So, make it openable only once.
Signed-off-by: NBrandon Philips <bphilips@suse.de>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Thanks to Jiri Slaby <jirislaby@gmail.com> for pointing this issue.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Due to date overflow, vivi were not working fine anymore.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

The previous code were a little bit messy. Cleans it up.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Avoids de-alocating buffers before finishing to fill a buffer
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

The changes at vivi_template make debug option to not work properly.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Manually fixed all pertinent checkpatch.pl errors inside the source code.

Also removed some unused code at the driver and a few minor cleanups.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

mv_count is a counter used to move the vertical bars. Before this patch, it
where a static var. This works fine for just one device. However, when using
multiple devices, every device would increment it.

This patch moves it to its correct place: struct vivi_dev. So, now, each device
has its own data.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Now, it is possible to open multiple vivi devices, by using n_devs parameter.
This makes vivi driver closer to a real one.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

There were a trouble at vivi driver when using non-zero inodes. This where due
to not properly preserving the minor inode after calling video_register. Since
this driver is a reference for newer drivers, and it is possible to have more
than one video device inside the machine, this patch makes vivi to dynamically
allocate video_device struct.

Thanks to Gregor Jasny <jasny@vidsoft.de> for pointing the issue.

Also, this patch removes a very anoying (but useless) message of not having a
proper release call.

CC: Gregor Jasny <jasny@vidsoft.de>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

s/STATE_NEEDS_INIT/VIDEOBUF_NEEDS_INIT/g
s/STATE_PREPARED/VIDEOBUF_PREPARED/g
s/STATE_QUEUED/VIDEOBUF_QUEUED/g
s/STATE_ACTIVE/VIDEOBUF_ACTIVE/g
s/STATE_DONE/VIDEOBUF_DONE/g
s/STATE_ERROR/VIDEOBUF_ERROR/g
s/STATE_IDLE/VIDEOBUF_IDLE/g
Signed-off-by: NBrandon Philips <bphilips@suse.de>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Drivers were using cookie cutter code for stopping the read/stream.  Use the
new videobuf_stop function which is lock safe.
Signed-off-by: NBrandon Philips <bphilips@suse.de>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

struct video_device used to define a .hardware field. While
initialized on severl drivers, this field is never used inside V4L.
However, drivers using it need to include the old V4L1 header.

This seems to cause compilation troubles with some random configs.
Better just to remove it from all drivers.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

The rest of V4L files.

There is one list_for_each+list_entry in cpia_pp.c that
wasn't changed because it expects the loop iterator to remain NULL if
the list is empty.

A bug in vivi is fixed; the 'safe' version needs to be used because the loop
deletes the list entries.

Simplify a second loop in vivi and get rid if an un-used variable in that loop.
Signed-off-by: NTrent Piepho <xyzzy@speakeasy.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Vivi driver is now simpler. This patch removes the now unused vars.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

The "resource" locking in vivi isn't needed since
streamon/streamoff/read_stream do mutual exclusion using
q->reading/q->streaming.

Plus it is sort of broken:

a) res_locked() use in vivi_read() is racey.
b) res_free() calls mutex_lock twice causing streamoff to break
Signed-off-by: NBrandon Philips <bphilips@suse.de>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Since vivi is using videobuf_read_stream() it can use videobuf_poll_stream()
now.
Signed-off-by: NBrandon Philips <bphilips@suse.de>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

If the client provides V4L2_FIELD_ANY vivi should return a valid field :)
Signed-off-by: NBrandon Philips <bphilips@suse.de>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

While this is not the standard color bar behaviour, having some movement
there allows to check if buffers are being properly handled.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Due to the replace of videobuf_read_one to videobuf_read_stream, poll()
method implementation is wrong. This fixes poll() implementation, making
read of /dev/video? to work again.

With this method, an USB driver can use video-buf, without needing to
request memory from the DMA-safe area.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

This patch removes the usage of videobuf-dma-sg from vivi driver, using
instead videobuf-vmalloc. This way, vivi will be useful for testing the
newer method. Reverting this patch won't hurt vivi, since both methods
work fine.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

videobuf_read_stream is more efficient than videobuf_read_one
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

The Virtual Video driver uses a semaphore as mutex. Use the mutex API
instead of the (binary) semaphore.
Signed-off-by: NMatthias Kaehlcke <matthias.kaehlcke@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

vivi scatter method were used as a proof of concept. It can be
safelly removed from mainstream, since the current method is
faster and better than the previous solution.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves.  This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.

It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.

The patch causes all kernel threads to be nonfreezable by default (ie.  to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE.  It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear.  Additionally, it updates documentation to
describe the freezing of tasks more accurately.

[akpm@linux-foundation.org: build fixes]
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NNigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The result of copy_to_user was not used, so the compiler complained
now a warning will be issued if copy_to_user fails.
Signed-off-by: NMarcel Siegert <mws@linuxtv.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Before this patch, vivi were simulating a scatter gather DMA transfer.
While this is academic, showing how stuff really works on a real PCI 
device, this means a non-optimized code. 
There are only two memory models that vivi implements:
	1) kernel alloced memory. This is also used by read() method.
	   On this case, a vmalloc32 buffer is allocated at kernel;
	2) userspace allocated memory. This is used by most userspace apps.
	   video-buf will store this pointer.
	   a simple copy_to_user is enough to transfer data.
The third memory model scenario supported by video-buf is overlay mode. 
This model is not implemented on vivi and unlikely to be implemented on 
newer drivers, since now, most userspace apps do some post-processing 
(like de-interlacing).
After this patch, some cleanups may be done at video-buf.c to avoid 
allocating pages, when the driver doesn't need a PCI buffer. This is the 
case of vivi and usb drivers.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

There are several potential troubles on vivi waitqueue code:
- Watchdog timer should be reset at every received frame;
- Watchdog timer should be reset at the beginning of vivi_thread();
- Checks for errors when creating a newer thread with kernel_thread();
- Wake up vivi_thread() after creating it.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

If for some reason vivi_thread() fails, vivi will suffer an OOPS at
thread stop code, since waitqueue wouldn't be properly initializated.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

[akpm@sdl.org: dvb fix]
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

vivi.c uses the KM_BOUNCE_READ with local interrupts enabled. 
This means that if a disk interrupt occurs while vivi.c is using this
fixmap slot, the vivi.c driver will, upon return from that interrupt, find
that the fixmap slot now points at a different physical page.
The net result will probably be rare corruption of disk file contents,
because viv.c will now be altering the page which the disk code was
recently using. 

Thanks to Andrew Morton for pointing this.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

The return value of kthread_run() should be checked by IS_ERR().
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Freeing data including list_head in list_for_each() is not safe.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

video_ioctl2 will auto-generate standard entries at ENUM_FMT.
Also, now, a driver may return a subset of the video array at
the return, to be stored as the current_norm.
For example, a driver may ask for V4L2_STD_PAL. At return,
driver may change it to V4L2_STD_PAL_B. This way, a futher call
to G_STD will return the exact detected video std.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Move process freezing functions from include/linux/sched.h to freezer.h, so
that modifications to the freezer or the kernel configuration don't require
recompiling just about everything.

[akpm@osdl.org: fix ueagle driver]
Signed-off-by: NNigel Cunningham <nigel@suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

parisc (and several other architectures) don't have a dma_address in their
sg list.  Use the macro instead.
Signed-off-by: NMatthew Wilcox <matthew@wil.cx>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>