ftrace: fix error with only one actor

When system has only one actor and call method trappy.summary_plots, it
will report failure "zip argument #1 must support iteration".

This failure is cause by parsing allfreqs plots. Python always pass by
value, so when there have only one actor the axis will pass by value and
it's not a array type anymore. So finally zip will report it cannot
support iteration. So in this case convert axis to array type.

Signed-off-by: Leo Yan <leo.yan@linaro.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/tests/test_ftrace.py b/tests/test_ftrace.py
index 82fa404..b594c1d 100644
--- a/tests/test_ftrace.py
+++ b/tests/test_ftrace.py
@@ -265,6 +265,22 @@ class TestFTrace(BaseTestThermal):
         trace.plot_allfreqs(self.map_label, ax=axis)
         matplotlib.pyplot.close('all')
 
+    def test_plot_allfreqs_with_one_actor(self):
+        """Check that plot_allfreqs() works with one actor"""
+
+        in_data = """     kworker/4:1-397   [004]   720.741349: thermal_power_cpu_get: cpus=00000000,00000006 freq=1400000 raw_cpu_power=189 load={23, 12} power=14
+     kworker/4:1-397   [004]   720.741349: thermal_power_cpu_limit: cpus=00000000,00000006 freq=1400000 cdev_state=1 power=14"""
+
+        with open("trace.txt", "w") as fout:
+            fout.write(in_data)
+
+        trace = trappy.FTrace()
+        map_label = {"00000000,00000006": "A57"}
+        _, axis = matplotlib.pyplot.subplots(nrows=1)
+
+        trace.plot_allfreqs(map_label, ax=axis)
+        matplotlib.pyplot.close('all')
+
     def test_trace_metadata(self):
         """Test if metadata gets populated correctly"""