diff --git a/jenkins/lava-submit.jpl b/jenkins/lava-submit.jpl
index efcc755..d2ed238 100644
--- a/jenkins/lava-submit.jpl
+++ b/jenkins/lava-submit.jpl
@@ -42,11 +42,27 @@
     }
     stage("LAVA") {
       def device_type = ""
-      def upstreamProject = getUpstreamJob()[0].upstreamProject
-      if (upstreamProject == "tf-m-build-and-test") {
-        device_type = "--physical-board-only "
-        print("Run test cases only on physical boards in per-patch.")
+
+      // For builds running per-patch (started by the tf-m-static job),
+      // run tests only on physical boards to improve turnaround/performance.
+      def upstream_job = getUpstreamJob()[0]
+      if (upstream_job instanceof hudson.model.Cause.UpstreamCause) {
+        def gp_causes = upstream_job.getUpstreamCauses()
+        if (gp_causes.size() > 0 && gp_causes[0] instanceof hudson.model.Cause.UpstreamCause) {
+          print("Grand-parent project cause: ")
+          println(gp_causes[0].upstreamProject)
+          if (gp_causes[0].upstreamProject.endsWith("tf-m-static")) {
+            device_type = "--physical-board-only "
+            print("Run test cases only on physical boards in tf-m-static.")
+          }
+        } else {
+          println("No grand-parent project cause.")
+        }
       }
+      // Workaround for Groovy CPS idiosyncrasies. See e.g.
+      // https://blog.thesparktree.com/you-dont-know-jenkins-part-3#solutions
+      upstream_job = null
+      gp_causes = null
 
       withCredentials([usernamePassword(credentialsId: env.LAVA_CREDENTIALS, passwordVariable: 'LAVA_TOKEN', usernameVariable: 'LAVA_USER')]) {
         print("Generating LAVA jobs...")