[media] cx88: fix locking of sub-driver operations

The BKL conversion of this driver seems to have gone wrong.
Loading the cx88-blackbird driver deadlocks.

The cause: mpeg_ops::open in the cx2388x blackbird driver acquires the
device lock and calls the sub-driver's request_acquire, which tries to
acquire the lock again.  Fix it by clarifying the semantics of
request_acquire, request_release, advise_acquire, and advise_release:
now all will rely on the caller to acquire the device lock.

Based on work by Ben Hutchings <[email protected]>.

Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=31962

Reported-by: Andi Huber <[email protected]>
Tested-by: Andi Huber <[email protected]>
Tested-by: Marlon de Boer <[email protected]>
Cc: [email protected]
Signed-off-by: Jonathan Nieder <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>

0 files changed, 0 insertions, 0 deletions