From f3f83174b15e69e47e4167c1cc53066fe11dd5e4 Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Tue, 31 Oct 2017 00:10:13 +0800
Subject: [PATCH] test: check that DMA can underflow

---
 artiq/test/coredevice/test_rtio.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/artiq/test/coredevice/test_rtio.py b/artiq/test/coredevice/test_rtio.py
index c968bb37e..13517084a 100644
--- a/artiq/test/coredevice/test_rtio.py
+++ b/artiq/test/coredevice/test_rtio.py
@@ -634,6 +634,12 @@ class DMATest(ExperimentCase):
         print("dt={}, dt/count={}".format(dt, dt/count))
         self.assertLess(dt/count, 4.5*us)
 
+    def test_dma_underflow(self):
+        exp = self.create(_DMA)
+        exp.record()
+        with self.assertRaises(RTIOUnderflow):
+            exp.playback_many(20000)
+
     def test_handle_invalidation(self):
         exp = self.create(_DMA)
         for mode in [0, 1]: