[PATCH] comedi: comedi_test: fix check for valid scan_begin_src in waveform_ai_cmdtest()

[Ian Abbott]

Commit 783ddaebd397 ("staging: comedi: comedi_test: support
scan_begin_src == TRIG_FOLLOW") neglected to add a test that
`scan_begin_src` has only one bit set.  The allowed values are
`TRIG_FOLLOW` and `TRIG_TIMER`, but the code incorrectly also allows
`TRIG_FOLLOW | TRIG_TIMER`.  Add a call to
`comedi_check_trigger_is_unique()` to check that only one trigger source
bit is set.

Fixes: 783ddaebd397 ("staging: comedi: comedi_test: support scan_begin_src == TRIG_FOLLOW")
Cc: <staging@xxxxxxxxxxxxxxx>
Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
---
 drivers/comedi/drivers/comedi_test.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/comedi/drivers/comedi_test.c b/drivers/comedi/drivers/comedi_test.c
index 01aafce20ef8..f586441d5981 100644
--- a/drivers/comedi/drivers/comedi_test.c
+++ b/drivers/comedi/drivers/comedi_test.c
@@ -274,6 +274,7 @@ static int waveform_ai_cmdtest(struct comedi_device *dev,
 	/* Step 2a : make sure trigger sources are unique */
 
 	err |= comedi_check_trigger_is_unique(cmd->convert_src);
+	err |= comedi_check_trigger_is_unique(cmd->scan_begin_src);
 	err |= comedi_check_trigger_is_unique(cmd->stop_src);
 
 	/* Step 2b : and mutually compatible */
-- 
2.53.0