[igt-dev] [PATCH i-g-t] test/amdgpu: Test max-bpc fallback for 4K modes on HDMI

[Stylon Wang <stylon.wang@amd.com>]

[Why]
There was a driver regression with which too high max-bpc setting
causes 4K video modes failing stream validation and dropped from
mode list.

[How]
Add this test to catch the regression.

Signed-off-by: Stylon Wang <stylon.wang@amd.com>
---
 tests/amdgpu/amd_max_bpc.c | 190 +++++++++++++++++++++++++++++++++++++
 tests/amdgpu/meson.build   |   1 +
 2 files changed, 191 insertions(+)
 create mode 100644 tests/amdgpu/amd_max_bpc.c

diff --git a/tests/amdgpu/amd_max_bpc.c b/tests/amdgpu/amd_max_bpc.c
new file mode 100644
index 00000000..914034d3
--- /dev/null
+++ b/tests/amdgpu/amd_max_bpc.c
@@ -0,0 +1,190 @@
+/*
+ * Copyright 2021 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include "igt.h"
+#include <fcntl.h>
+
+IGT_TEST_DESCRIPT("Test 4K HDMI regression if max bpc is too high");
+
+/* Common test data. */
+typedef struct data {
+	igt_display_t display;
+	igt_plane_t *primary;
+	igt_output_t *output;
+	igt_pipe_t *pipe;
+	igt_pipe_crc_t *pipe_crc;
+	igt_pipe_crc_t *pipe_crc_dither;
+	drmModeModeInfo *mode;
+	enum pipe pipe_id;
+	int fd;
+	int w;
+	int h;
+} data_t;
+
+/* BPC connector state. */
+typedef struct output_bpc {
+	unsigned int current;
+	unsigned int maximum;
+} output_bpc_t;
+
+static drmModeModeInfo uhd_mode = {
+	  594000,
+	  3840, 4016, 4104, 4400, 0,
+	  2160, 2168, 2178, 2250, 0,
+	  60, 0x5|DRM_MODE_FLAG_PIC_AR_64_27,
+	  0x40,
+	  "3840x2160@60", /* VIC 107 */
+	  };
+
+/* Returns the current and maximum bpc from the connector debugfs. */
+static output_bpc_t get_output_bpc(data_t *data)
+{
+	char buf[256];
+	char *start_loc;
+	int fd, res;
+	output_bpc_t info;
+
+	fd = igt_debugfs_connector_dir(data->fd, data->output->name, O_RDONLY);
+	igt_assert(fd >= 0);
+
+	res = igt_debugfs_simple_read(fd, "output_bpc", buf, sizeof(buf));
+
+	igt_require(res > 0);
+
+	close(fd);
+
+	igt_assert(start_loc = strstr(buf, "Current: "));
+	igt_assert_eq(sscanf(start_loc, "Current: %u", &info.current), 1);
+
+	igt_assert(start_loc = strstr(buf, "Maximum: "));
+	igt_assert_eq(sscanf(start_loc, "Maximum: %u", &info.maximum), 1);
+
+	return info;
+}
+
+/* Verifies that connector has the correct output bpc. */
+static void assert_output_bpc(data_t *data, unsigned int bpc)
+{
+	output_bpc_t info = get_output_bpc(data);
+
+	igt_require_f(info.maximum >= bpc,
+		      "Monitor doesn't support %u bpc, max is %u\n", bpc,
+		      info.maximum);
+
+	igt_assert_eq(info.current, bpc);
+}
+
+/* Common test setup. */
+static void test_init(data_t *data)
+{
+	igt_display_t *display = &data->display;
+
+	/* It doesn't matter which pipe we choose on amdpgu. */
+	data->pipe_id = PIPE_A;
+	data->pipe = &data->display.pipes[data->pipe_id];
+
+	igt_display_reset(display);
+
+	/* find a connected HDMI output */
+	data->output = NULL;
+	for (int i=0; i < data->display.n_outputs; ++i) {
+		drmModeConnector *connector = data->display.outputs[i].config.connector;
+		if (connector->connection == DRM_MODE_CONNECTED &&
+				(connector->connector_type == DRM_MODE_CONNECTOR_HDMIA)) {
+			data->output = &data->display.outputs[i];
+		}
+	}
+	igt_assert_f(data->output, "Requires connected HDMI output\n");
+
+	igt_output_set_prop_value(data->output, IGT_CONNECTOR_MAX_BPC, 10);
+	igt_output_override_mode(data->output, &uhd_mode);
+
+	data->mode = igt_output_get_mode(data->output);
+	igt_assert(data->mode);
+	assert_output_bpc(data, 8);
+
+	data->primary =
+		igt_pipe_get_plane_type(data->pipe, DRM_PLANE_TYPE_PRIMARY);
+
+	data->pipe_crc = igt_pipe_crc_new(data->fd, data->pipe_id,
+					  INTEL_PIPE_CRC_SOURCE_AUTO);
+
+	igt_output_set_pipe(data->output, data->pipe_id);
+
+	data->w = data->mode->hdisplay;
+	data->h = data->mode->vdisplay;
+}
+
+/* Common test cleanup. */
+static void test_fini(data_t *data)
+{
+	igt_pipe_crc_free(data->pipe_crc);
+	igt_display_reset(&data->display);
+}
+
+static void test_4k_mode_max_bpc(data_t *data)
+{
+	igt_display_t *display = &data->display;
+	igt_fb_t rfb;
+	int max_bpc = 16;
+
+	test_init(data);
+
+	igt_info("Setting output max bpc to %d\n", max_bpc);
+
+	igt_output_set_prop_value(data->output, IGT_CONNECTOR_MAX_BPC, max_bpc);
+
+	igt_create_pattern_fb(data->fd, data->w, data->h, DRM_FORMAT_XRGB8888, 0, &rfb);
+	igt_plane_set_fb(data->primary, &rfb);
+	igt_display_commit_atomic(display, DRM_MODE_ATOMIC_ALLOW_MODESET, NULL);
+
+	test_fini(data);
+	igt_remove_fb(data->fd, &rfb);
+}
+
+igt_main
+{
+	data_t data;
+
+	igt_skip_on_simulation();
+
+	memset(&data, 0, sizeof(data));
+
+	igt_fixture
+	{
+		data.fd = drm_open_driver_master(DRIVER_AMDGPU);
+
+		kmstest_set_vt_graphics_mode();
+
+		igt_display_require(&data.display, data.fd);
+		igt_require(data.display.is_atomic);
+		igt_display_require_output(&data.display);
+	}
+
+	igt_describe("Tests overly high 'max bpc' should not affect 4K modes on HDMI");
+	igt_subtest("4k-mode-max-bpc") test_4k_mode_max_bpc(&data);
+
+	igt_fixture
+	{
+		igt_display_fini(&data.display);
+	}
+}
diff --git a/tests/amdgpu/meson.build b/tests/amdgpu/meson.build
index aec71cb5..b736c456 100644
--- a/tests/amdgpu/meson.build
+++ b/tests/amdgpu/meson.build
@@ -11,6 +11,7 @@ if libdrm_amdgpu.found()
 			  'amd_hotplug',
 			  'amd_info',
 			  'amd_prime',
+			  'amd_max_bpc',
 			  'amd_module_load',
 			  'amd_mem_leak',
 			  'amd_link_settings',
-- 
2.32.0