lib/tests: Add kmstest_edid_add_* selftests

Sanity check the edid block generation capabilities.

Cc: Petri Latvala <petri.latvala@intel.com>
Reviewed-by: Petri Latvala <petri.latvala@intel.com>
Signed-off-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>

3 files changed, 98 insertions, 0 deletions

diff --git a/lib/tests/.gitignore b/lib/tests/.gitignore
index 842482c0..12a3712c 100644
--- a/lib/tests/.gitignore
+++ b/lib/tests/.gitignore
@@ -13,3 +13,4 @@ igt_simulation
 igt_stats
 igt_subtest_group
 igt_timeout
+igt_hdmi_inject
diff --git a/lib/tests/Makefile.sources b/lib/tests/Makefile.sources
index 3fcfe141..4cfc0a53 100644
--- a/lib/tests/Makefile.sources
+++ b/lib/tests/Makefile.sources
@@ -13,6 +13,7 @@ check_prog_list = \
 	igt_subtest_group \
 	igt_assert \
 	igt_exit_handler \
+	igt_hdmi_inject \
 	$(NULL)
 
 TESTS = \
diff --git a/lib/tests/igt_hdmi_inject.c b/lib/tests/igt_hdmi_inject.c
new file mode 100644
index 00000000..9b6780a1
--- /dev/null
+++ b/lib/tests/igt_hdmi_inject.c
@@ -0,0 +1,96 @@
+/*
+ * Copyright © 2017 Intel Corporation
+ *
+ * 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 (including the next
+ * paragraph) 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 AUTHORS OR COPYRIGHT HOLDERS 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"
+
+static const unsigned char edid_header[] = {
+	0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00
+};
+
+/**
+ * Sanity check the header of the base EDID block.
+ *
+ * Return: 8 if the header is perfect, down to 0 if it's totally wrong.
+ */
+static int edid_header_is_valid(const unsigned char *raw_edid)
+{
+	int i, score = 0;
+
+	for (i = 0; i < sizeof(edid_header); i++)
+		if (raw_edid[i] == edid_header[i])
+			score++;
+
+	return score;
+}
+
+/**
+ * Sanity check the checksum of the EDID block.
+ *
+ * Return: 0 if the block is perfect.
+ * See byte 127 of spec
+ * https://en.wikipedia.org/wiki/Extended_Display_Identification_Data#EDID_1.3_data_format
+ */
+static int edid_block_checksum(const unsigned char *raw_edid)
+{
+	int i;
+	unsigned char csum = 0;
+	for (i = 0; i < EDID_LENGTH; i++) {
+		csum += raw_edid[i];
+	}
+
+	return csum;
+}
+
+typedef void (*hdmi_inject_func)(const unsigned char *edid, size_t length,
+				 unsigned char *new_edid_ptr[], size_t *new_length);
+
+igt_simple_main
+{
+	const struct {
+		const char *desc;
+		hdmi_inject_func inject;
+	} funcs[] = {
+		{ "3D", kmstest_edid_add_3d },
+		{ "4k", kmstest_edid_add_4k },
+		{ "audio", kmstest_edid_add_audio },
+		{ NULL, NULL },
+	}, *f;
+
+	for (f = funcs; f->inject; f++) {
+		unsigned char *edid;
+		size_t length;
+
+		f->inject(igt_kms_get_base_edid(), EDID_LENGTH, &edid,
+			  &length);
+
+		igt_assert_f(edid_header_is_valid(edid) == 8,
+			     "invalid header on HDMI %s", f->desc);
+		/* check base edid block */
+		igt_assert_f(edid_block_checksum(edid) == 0,
+			     "checksum failed on HDMI %s", f->desc);
+		/* check extension block */
+		igt_assert_f(edid_block_checksum(edid + EDID_LENGTH) == 0,
+			     "CEA block checksum failed on HDMI %s", f->desc);
+	}
+}