stm class: Fix channel free in stm output free path

commit ee496da4c3915de3232b5f5cd20e21ae3e46fe8d upstream.

Number of free masters is not set correctly in stm
free path. Fix this by properly adding the number
of output channels before setting them to 0 in
stm_output_disclaim().

Currently it is equivalent to doing nothing since
master->nr_free is incremented by 0.

Fixes: 7bd1d4093c2f ("stm class: Introduce an abstraction for System Trace Module devices")
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Cc: stable@vger.kernel.org # v4.4
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
index 9d55e104400c8670b557574ca8c3f2d63389b996..1caca7376e747317e9564ebea5a32706a030e105 100644 (file)
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -218,8 +218,8 @@ stm_output_disclaim(struct stm_device *stm, struct stm_output *output)
        bitmap_release_region(&master->chan_map[0], output->channel,
                              ilog2(output->nr_chans));
 
-       output->nr_chans = 0;
        master->nr_free += output->nr_chans;
+       output->nr_chans = 0;
 }
 
 /*