tests/flip_test: check whether timestamp isn't in the past

This is mostly useful for when we add support for other clock sources,
e.g. clock_monotic, to check whether the kernel picked the right
clock.

diff --git a/tests/flip_test.c b/tests/flip_test.c
index 4f23155..1ae6f80 100644 (file)
--- a/tests/flip_test.c
+++ b/tests/flip_test.c
@@ -70,6 +70,7 @@ struct test_output {
        unsigned int current_fb_id;
        unsigned int fb_ids[2];
        struct kmstest_fb fb_info[2];
+       struct timeval last_flip_ts;
 };
 
 static void emit_dummy_load(struct test_output *o)
@@ -166,6 +167,11 @@ static void page_flip_handler(int fd, unsigned int frame, unsigned int sec,
                exit(5);
        }
 
+       if (!timercmp(&o->last_flip_ts, &now, <)) {
+               fprintf(stderr, "pageflip ts before the pageflip was issued!\n");
+               exit(6);
+       }
+
        o->count++;
 
        o->current_fb_id = !o->current_fb_id;
@@ -183,6 +189,8 @@ static void page_flip_handler(int fd, unsigned int frame, unsigned int sec,
 
        if (o->flags & TEST_DPMS)
                do_or_die(set_dpms(o, DRM_MODE_DPMS_OFF));
+
+       o->last_flip_ts = now;
 }
 
 static void connector_find_preferred_mode(struct test_output *o, int crtc_id)
@@ -358,6 +366,7 @@ static void flip_mode(struct test_output *o, int crtc, int duration)
        evctx.page_flip_handler = page_flip_handler;
 
        gettimeofday(&end, NULL);
+       gettimeofday(&o->last_flip_ts, NULL);
        end.tv_sec += duration;
 
        while (1) {