diff --git a/src/jtag/jtag.c b/src/jtag/jtag.c
index 2432516a34898ad99f230c1ed97d7ad418963d5a..eba095495aef80c20ece6bc39db79f927e91084a 100644
--- a/src/jtag/jtag.c
+++ b/src/jtag/jtag.c
@@ -1417,11 +1417,23 @@ void jtag_set_check_value(scan_field_t *field, u8 *value, u8 *mask, struct inval
 
 void jtag_check_value_mask(scan_field_t *field, u8 *value, u8 *mask)
 {
+	if (field->in_value==NULL)
+	{
+		LOG_ERROR("remember to fill in in_value for jtag_check_value_mask() to work!");
+		return;
+	}
+
+	if (value==NULL)
+	{
+		/* no checking to do */
+		return;
+	}
+
 	jtag_execute_queue_noclear();
-	
+
 	int retval=jtag_check_value_inner(field->in_value, field, value, mask);
 	jtag_set_error(retval);
-	
+
 }
 
 
diff --git a/src/target/embeddedice.c b/src/target/embeddedice.c
index aa5aacec4c529aa685b28ca618e73ac19e9452e3..363d182e5cef2761ea379bd17b2743cbf2943ab9 100644
--- a/src/target/embeddedice.c
+++ b/src/target/embeddedice.c
@@ -251,39 +251,26 @@ int embeddedice_read_reg_w_check(reg_t *reg, u8* check_value, u8* check_mask)
 	fields[0].tap = ice_reg->jtag_info->tap;
 	fields[0].num_bits = 32;
 	fields[0].out_value = reg->value;
-
 	fields[0].in_value = NULL;
-
-
 	fields[0].in_handler = NULL;
 
-
 	fields[1].tap = ice_reg->jtag_info->tap;
 	fields[1].num_bits = 5;
 	fields[1].out_value = field1_out;
 	buf_set_u32(fields[1].out_value, 0, 5, reg_addr);
-
 	fields[1].in_value = NULL;
-
-
 	fields[1].in_handler = NULL;
 
-
 	fields[2].tap = ice_reg->jtag_info->tap;
 	fields[2].num_bits = 1;
 	fields[2].out_value = field2_out;
 	buf_set_u32(fields[2].out_value, 0, 1, 0);
-
 	fields[2].in_value = NULL;
-
-
 	fields[2].in_handler = NULL;
 
-
 	jtag_add_dr_scan(3, fields, TAP_INVALID);
 
 	fields[0].in_value = reg->value;
-	jtag_set_check_value(fields+0, check_value, check_mask, NULL);
 
 	/* when reading the DCC data register, leaving the address field set to
 	 * EICE_COMMS_DATA would read the register twice
@@ -293,6 +280,8 @@ int embeddedice_read_reg_w_check(reg_t *reg, u8* check_value, u8* check_mask)
 
 	jtag_add_dr_scan(3, fields, TAP_INVALID);
 
+	jtag_check_value_mask(fields+0, check_value, check_mask);
+
 	return ERROR_OK;
 }