coresight: Move reference counting inside sink drivers

When operating in CPU-wide mode with an N:1 source/sink HW topology,
multiple CPUs can access a sink concurrently.  As such reference counting
needs to happen when the device's spinlock is held to avoid racing with
other operations (start(), update(), stop()), such as:

session A				Session B
-----					-------

enable_sink
atomic_inc(refcount)  = 1

...

atomic_dec(refcount) = 0		enable_sink
if (refcount == 0) disable_sink
					atomic_inc()

Signed-off-by: Mathieu Poirier <[email protected]>
Reviewed-by: Suzuki K Poulose <[email protected]>
Tested-by: Leo Yan <[email protected]>
Tested-by: Robert Walker <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

0 files changed, 0 insertions, 0 deletions