[Intel-gfx] [PATCH igt 6/6] kms_frontbuffer_tracking: add fliptrack subtest

[Paulo Zanoni]

The current upstream Kernel code stops and then restarts FBC at every
page flip. I am working on patches to keep FBC enabled all the time,
so this brings the possibility of having the hardware tracking
mechanism looking at the old buffer instead of the new one. This test
should catch this problem.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
---
 tests/kms_frontbuffer_tracking.c | 63 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

diff --git a/tests/kms_frontbuffer_tracking.c b/tests/kms_frontbuffer_tracking.c
index 94b9e01..d97e148 100644
--- a/tests/kms_frontbuffer_tracking.c
+++ b/tests/kms_frontbuffer_tracking.c
@@ -2265,6 +2265,54 @@ static void flip_subtest(const struct test_mode *t, enum flip_type type)
 }
 
 /*
+ * fliptrack - check if the hardware tracking works after page flips
+ *
+ * METHOD
+ *   Flip to a new buffer, then draw on it using MMAP_GTT and check the CRC to
+ *   make sure the hardware tracking detected the write.
+ *
+ * EXPECTED RESULTS
+ *   Everything works as expected, screen contents are properly updated.
+ *
+ * FAILURES
+ *   First you need to check if the draw and flip subtests pass. Only after both
+ *   are passing this test can be useful. If we're failing only on this subtest,
+ *   then maybe we are not properly updating the hardware tracking registers
+ *   during the flip operations.
+ */
+static void fliptrack_subtest(const struct test_mode *t, enum flip_type type)
+{
+	int r;
+	struct igt_fb fb2, *orig_fb;
+	struct modeset_params *params = pick_params(t);
+	struct draw_pattern_info *pattern = &pattern1;
+
+	prepare_subtest(t, pattern);
+
+	create_fb(t->format, params->fb.fb->width, params->fb.fb->height,
+		  LOCAL_I915_FORMAT_MOD_X_TILED, t->plane, &fb2);
+	fill_fb(&fb2, COLOR_PRIM_BG);
+	orig_fb = params->fb.fb;
+
+	for (r = 0; r < pattern->n_rects; r++) {
+		params->fb.fb = (r % 2 == 0) ? &fb2 : orig_fb;
+
+		if (r != 0)
+			draw_rect(pattern, &params->fb, t->method, r - 1);
+
+		page_flip_for_params(params, type);
+		do_assertions(0);
+
+		draw_rect(pattern, &params->fb, t->method, r);
+		update_wanted_crc(t, &pattern->crcs[t->format][r]);
+
+		do_assertions(ASSERT_PSR_DISABLED);
+	}
+
+	igt_remove_fb(drm.fd, &fb2);
+}
+
+/*
  * move - just move the sprite or cursor around
  *
  * METHOD
@@ -3098,6 +3146,21 @@ int main(int argc, char *argv[])
 			      fbs_str(t.fbs),
 			      igt_draw_get_method_name(t.method))
 			flip_subtest(&t, FLIP_MODESET);
+
+	TEST_MODE_ITER_END
+
+	TEST_MODE_ITER_BEGIN(t)
+		if (t.plane != PLANE_PRI ||
+		    t.screen != SCREEN_PRIM ||
+		    t.method != IGT_DRAW_MMAP_GTT ||
+		    (t.feature & FEATURE_FBC) == 0)
+			continue;
+
+		igt_subtest_f("%s-%s-%s-fliptrack",
+			      feature_str(t.feature),
+			      pipes_str(t.pipes),
+			      fbs_str(t.fbs))
+			fliptrack_subtest(&t, FLIP_PAGEFLIP);
 	TEST_MODE_ITER_END
 
 	TEST_MODE_ITER_BEGIN(t)
-- 
2.5.3