cx18: Fix cx18_find_handle() and add error checking.  cx18_find_handle() did
not find a good task handle and would use the invalid task handle under common
conditions.  Added a define for the invalid task handle and added error checking
as well.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

cx18: Convert cx18_queue buffers member to atomic_t.  This allows safe
concurrent access to check if a queue has data without having to acquire the
queue spinlock.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

cx18: Remove redundant struct cx18_queue length member. It can be trivially
computed from queue->buffers * stream->buf_size, if ever really needed.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

The HVR-1600 can do both analog and digital capture at the same time.
Due to a driver bug -EBUSY would be returned when attempting to setup an
analog capture while a digital capture was already in progress.

Separate the two internally.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Upon error conditions in cx18/ivtv_probe(), the code at the 'err:' label
leaves a NULL entry in cx18/ivtv_cards[]. This can cause a NULL pointer
de-reference in cx18/ivtv_v4l2_open() which is fixed by this patch.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

This patch contains the following possible cleanups:
- cx18-i2c.c should #include "cx18-i2c.h" for getting the prototypes of
  it's global functions
- make the following needlessly global functions static:
  - cx18-fileops.c:cx18_claim_stream()
  - cx18-fileops.c:cx18_release_stream()
  - cx18-queue.c:cx18_queue_move()
- remove the following unused functions:
  - cx18-driver.c:cx18_waitq()
  - cx18-queue.c:cx18_buf_copy_from_user()
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Reviewed-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Many thanks to Steve Toth from Hauppauge and Nattu Dakshinamurthy from
Conexant for their support. I am in particular thankful to Hauppauge
since without their help this driver would not exist. It should also
be noted that Steve did the work to get the DVB part up and running.
Thank you!
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NSteven Toth <stoth@hauppauge.com>
Signed-off-by: NMichael Krufky <mkrufky@linuxtv.org>
Signed-off-by: NG. Andrew Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>