tree cec9345ab6f19e26711d20e0642956bed8fccd20
parent 2fdf3d9c94f7f752dacbebb75bbecda3c1b082a0
author Pantelis Koukousoulas <pakt223@freemail.gr> 1167271735 -0300
committer Mauro Carvalho Chehab <mchehab@infradead.org> 1172072063 -0200

V4L/DVB (5038): Pvrusb2: Implement stream claim checking function

Add (and expose) a new function, pvr2_channel_check_stream_no_lock(), in
pvrusb2-context.c. This is hopefully the last V4L2 interface related patch
to change anything outside pvrusb2-v4l2.c.

We need this to implement the open() for the radio device. The reason is
that within the *enter_context() section of open() we need to ensure nobody
is streaming and if we cannot, we should cleanup after ourselves and return
 -EBUSY. We cannot just use claim_stream() because:

   1) That would cause a deadlock trying to re-acquire the context lock
   2) We only need to ensure that nobody is streaming. We don't need to
      actually acquire the stream.

Again, this is a kinda ugly patch. Feel free to improve.

Signed-off-by: Pantelis Koukousoulas <pakt223@freemail.gr>
Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>