diff --git a/drivers/staging/comedi/drivers/addi_apci_1500.c b/drivers/staging/comedi/drivers/addi_apci_1500.c
index 63991c49ff23..79a8799b1262 100644
--- a/drivers/staging/comedi/drivers/addi_apci_1500.c
+++ b/drivers/staging/comedi/drivers/addi_apci_1500.c
@@ -465,9 +465,9 @@ static int apci1500_di_cfg_trig(struct comedi_device *dev,
 	unsigned int lo_mask = data[5] << shift;
 	unsigned int chan_mask = hi_mask | lo_mask;
 	unsigned int old_mask = (1 << shift) - 1;
-	unsigned int pm = devpriv->pm[trig] & old_mask;
-	unsigned int pt = devpriv->pt[trig] & old_mask;
-	unsigned int pp = devpriv->pp[trig] & old_mask;
+	unsigned int pm;
+	unsigned int pt;
+	unsigned int pp;
 
 	if (trig > 1) {
 		dev_dbg(dev->class_dev,
@@ -480,6 +480,10 @@ static int apci1500_di_cfg_trig(struct comedi_device *dev,
 		return -EINVAL;
 	}
 
+	pm = devpriv->pm[trig] & old_mask;
+	pt = devpriv->pt[trig] & old_mask;
+	pp = devpriv->pp[trig] & old_mask;
+
 	switch (data[2]) {
 	case COMEDI_DIGITAL_TRIG_DISABLE:
 		/* clear trigger configuration */