tests: Wait for radio work to start after DPP_LISTEN command

Since DPP listen is a radio work, it doesn't start immediately and
then we can end up missing whatever happens next in the test. Wait
for the radio work to start before continuing the test.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

tests/hwsim/wpasupplicant.py

@@ -1545,6 +1545,15 @@ class WpaSupplicant:
             cmd += " role=" + role
         if "OK" not in self.request(cmd):
             raise Exception("Failed to start listen operation")
+        # Since DPP listen is a radio work, make sure it has started
+        # by the time we return and continue with the test, since it
+        # usually will send something this side should receive.
+        work_started = "dpp-listen@" + self.ifname + ":" + str(freq) + ":1"
+        for i in range(10):
+            if work_started in self.request("RADIO_WORK show"):
+                return
+            time.sleep(0.01)
+        raise Exception("Failed to start DPP listen work")
 
     def dpp_auth_init(self, peer=None, uri=None, conf=None, configurator=None,
                       extra=None, own=None, role=None, neg_freq=None,