[igt-dev] [PATCH i-g-t] tests/kms_big_fb: Add max HW stride length tests

[Juha-Pekka Heikkila]

Test maximum HW stride lenghts. On Intel HW up to Gen10
maximum HW stride lenght is 32K. On Gen11 when using 64bpp
formats strides can reach up to 64k. These test try exact
maximum HW strides so gtt remapping will not come in play.

v2: (Ville Syrjäjä) Build new tests to run using existing code.

Signed-off-by: Juha-Pekka Heikkila <juhapekka.heikkila at gmail.com>
---
 tests/kms_big_fb.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 68 insertions(+), 3 deletions(-)

diff --git a/tests/kms_big_fb.c b/tests/kms_big_fb.c
index c3498c6..de24feb 100644
--- a/tests/kms_big_fb.c
+++ b/tests/kms_big_fb.c
@@ -48,6 +48,9 @@ typedef struct {
 	igt_render_copyfunc_t render_copy;
 	drm_intel_bufmgr *bufmgr;
 	struct intel_batchbuffer *batch;
+	bool max_hw_stride_test;
+	int hw_stride;
+	int max_hw_fb_width;
 } data_t;
 
 static void init_buf(data_t *data,
@@ -161,9 +164,6 @@ static void max_fb_size(data_t *data, int *width, int *height,
 	uint64_t size;
 	int i = 0;
 
-	*width = data->max_fb_width;
-	*height = data->max_fb_height;
-
 	/* max fence stride is only 8k bytes on gen3 */
 	if (intel_gen(data->devid) < 4 &&
 	    format == DRM_FORMAT_XRGB8888)
@@ -417,6 +417,14 @@ static bool test_pipe(data_t *data)
 
 static void test_scanout(data_t *data)
 {
+	if (data->max_hw_stride_test) {
+		data->big_fb_width = data->max_hw_fb_width;
+		data->big_fb_height = data->max_hw_fb_width;
+	} else {
+		data->big_fb_width = data->max_fb_width;
+		data->big_fb_height = data->max_fb_height;
+	}
+
 	max_fb_size(data, &data->big_fb_width, &data->big_fb_height,
 		    data->format, data->modifier);
 
@@ -649,6 +657,8 @@ igt_main
 
 		data.bufmgr = drm_intel_bufmgr_gem_init(data.drm_fd, 4096);
 		data.batch = intel_batchbuffer_alloc(data.bufmgr, data.devid);
+
+		data.max_hw_stride_test = false;
 	}
 
 	/*
@@ -704,6 +714,61 @@ igt_main
 		}
 	}
 
+	data.max_hw_stride_test = true;
+	for (int i = 0; i < ARRAY_SIZE(modifiers); i++) {
+		data.modifier = modifiers[i].modifier;
+
+		if (intel_gen(data.devid) < 11) {
+			data.hw_stride = 32768;
+		} else {
+			switch (data.modifier) {
+			case DRM_FORMAT_MOD_LINEAR:
+				data.hw_stride = 65536-64;
+				break;
+			default:
+				data.hw_stride = 65536;
+				break;
+			}
+		}
+
+		for (int j = 0; j < ARRAY_SIZE(formats); j++) {
+			/*
+			 * try only those formats which can show full lenght. 8K is
+			 * the magic maximum pixels in Intel HW. Here 32K is used
+			 * to have CI test results consistent for all platforms,
+			 * 32K is smallest number possbily coming to hw_stride
+			 * from above if{}else{}..
+			 */
+			if (32768 / (formats[j].bpp >> 3) > 8192)
+				continue;
+
+			data.format = formats[j].format;
+
+			for (int k = 0; k < ARRAY_SIZE(rotations); k++) {
+				data.rotation = rotations[k].rotation;
+				/*
+				 * Seems any format currently coming here will not support
+				 * 90/270 rotations so skip those rotations.
+				 */
+				if (data.rotation&(IGT_ROTATION_90|IGT_ROTATION_270))
+					continue;
+
+				igt_subtest_f("%s-max-hw-stride-%dbpp-rotate-%d", modifiers[i].name,
+					      formats[j].bpp, rotations[k].angle) {
+					data.max_hw_fb_width = data.hw_stride / (formats[j].bpp >> 3);
+					igt_require(data.format == DRM_FORMAT_C8 ||
+						    igt_fb_supported_format(data.format));
+					igt_require(igt_display_has_format_mod(&data.display, data.format, data.modifier));
+					test_scanout(&data);
+				}
+			}
+
+			igt_fixture
+				cleanup_fb(&data);
+		}
+	}
+	data.max_hw_stride_test = false;
+
 	igt_fixture {
 		igt_display_fini(&data.display);
 
-- 
2.7.4