comm_analyzer: fix data without any spi reads

closes #1050
2018-06-06 12:21:42 +02:00 · 2018-06-06 12:21:42 +02:00 · 38971d130a
parent e21b7965b9
commit 38971d130a
1 changed files with 2 additions and 1 deletions
--- a/artiq/coredevice/comm_analyzer.py
+++ b/artiq/coredevice/comm_analyzer.py
@ -381,7 +381,8 @@ class SPIMaster2Handler(WishboneHandler):
            else:
                raise ValueError("bad address", address)
            # process untimed reads and insert them here
-            while self._reads[0].rtio_counter < message.timestamp:
+            while (self._reads and
+                   self._reads[0].rtio_counter < message.timestamp):
                read = self._reads.pop(0)
                logger.debug("SPI read @%d data=0x%08x",
                            read.rtio_counter, read.data)