stm class: Use a signed return type for stm_find_master_chan

Author: Lucas Tanure <>

The return type "unsigned int" was used by the stm_find_master_chan function
despite of the aspect that it will eventually return a negative error code.

Done with the help of Coccinelle.

Signed-off-by: Lucas Tanure 
Signed-off-by: Alexander Shishkin 
Signed-off-by: Greg Kroah-Hartman 
 drivers/hwtracing/stm/core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
index aef8ddb..cdec240 100644
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -233,7 +233,7 @@ static int find_free_channels(unsigned long *bitmap, unsigned int start,
 	return -1;
-static unsigned int
+static int
 stm_find_master_chan(struct stm_device *stm, unsigned int width,
 		     unsigned int *mstart, unsigned int mend,
 		     unsigned int *cstart, unsigned int cend)
@@ -293,7 +293,7 @@ static int stm_output_assign(struct stm_device *stm, unsigned int width,
 		goto unlock;
 	ret = stm_find_master_chan(stm, width, &midx, mend, &cidx, cend);
-	if (ret)
+	if (ret < 0)
 		goto unlock;
 	output->master = midx;