drivers/gpu/drm/tests/drm_dp_mst_helper_test.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Test cases for the DRM DP MST helpers
  *
  * Copyright (c) 2022 Maíra Canal <mairacanal@riseup.net>
  */

 #include <kunit/test.h>

 #include <drm/display/drm_dp_mst_helper.h>
 #include <drm/drm_print.h>

 #include "../display/drm_dp_mst_topology_internal.h"

 struct drm_dp_mst_calc_pbn_mode_test {
 	const int clock;
 	const int bpp;
 	const bool dsc;
 	const int expected;
 };

 static const struct drm_dp_mst_calc_pbn_mode_test drm_dp_mst_calc_pbn_mode_cases[] = {
 	{
 		.clock = 154000,
 		.bpp = 30,
 		.dsc = false,
 		.expected = 689
 	},
 	{
 		.clock = 234000,
 		.bpp = 30,
 		.dsc = false,
 		.expected = 1047
 	},
 	{
 		.clock = 297000,
 		.bpp = 24,
 		.dsc = false,
 		.expected = 1063
 	},
 	{
 		.clock = 332880,
 		.bpp = 24,
 		.dsc = true,
 		.expected = 1191
 	},
 	{
 		.clock = 324540,
 		.bpp = 24,
 		.dsc = true,
 		.expected = 1161
 	},
 };

 static void drm_test_dp_mst_calc_pbn_mode(struct kunit *test)
 {
 	const struct drm_dp_mst_calc_pbn_mode_test *params = test->param_value;

 	KUNIT_EXPECT_EQ(test, drm_dp_calc_pbn_mode(params->clock, params->bpp << 4),
 			params->expected);
 }

 static void dp_mst_calc_pbn_mode_desc(const struct drm_dp_mst_calc_pbn_mode_test *t, char *desc)
 {
 	sprintf(desc, "Clock %d BPP %d DSC %s", t->clock, t->bpp, t->dsc ? "enabled" : "disabled");
 }

 KUNIT_ARRAY_PARAM(drm_dp_mst_calc_pbn_mode, drm_dp_mst_calc_pbn_mode_cases,
 		  dp_mst_calc_pbn_mode_desc);

 struct drm_dp_mst_calc_pbn_div_test {
 	int link_rate;
 	int lane_count;
 	fixed20_12 expected;
 };

 #define fp_init(__int, __frac) { \
 	.full = (__int) * (1 << 12) + \
 		(__frac) * (1 << 12) / 100000 \
 }

 static const struct drm_dp_mst_calc_pbn_div_test drm_dp_mst_calc_pbn_div_dp1_4_cases[] = {
 	/*
 	 * UHBR rates (DP Standard v2.1 2.7.6.3, specifying the rounded to
 	 *             closest value to 2 decimal places):
 	 * .expected = .link_rate * .lane_count * 0.9671 / 8 / 54 / 100
 	 * DP1.4 rates (DP Standard v2.1 2.6.4.2):
 	 * .expected = .link_rate * .lane_count * 0.8000 / 8 / 54 / 100
 	 *
 	 * truncated to 5 decimal places.
 	 */
 	{
 		.link_rate = 2000000,
 		.lane_count = 4,
 		.expected = fp_init(179,  9259),  /* 179.09259 */
 	},
 	{
 		.link_rate = 2000000,
 		.lane_count = 2,
 		.expected = fp_init(89, 54629),
 	},
 	{
 		.link_rate = 2000000,
 		.lane_count = 1,
 		.expected = fp_init(44, 77314),
 	},
 	{
 		.link_rate = 1350000,
 		.lane_count = 4,
 		.expected = fp_init(120, 88750),
 	},
 	{
 		.link_rate = 1350000,
 		.lane_count = 2,
 		.expected = fp_init(60, 44375),
 	},
 	{
 		.link_rate = 1350000,
 		.lane_count = 1,
 		.expected = fp_init(30, 22187),
 	},
 	{
 		.link_rate = 1000000,
 		.lane_count = 4,
 		.expected = fp_init(89, 54629),
 	},
 	{
 		.link_rate = 1000000,
 		.lane_count = 2,
 		.expected = fp_init(44, 77314),
 	},
 	{
 		.link_rate = 1000000,
 		.lane_count = 1,
 		.expected = fp_init(22, 38657),
 	},
 	{
 		.link_rate = 810000,
 		.lane_count = 4,
 		.expected = fp_init(60, 0),
 	},
 	{
 		.link_rate = 810000,
 		.lane_count = 2,
 		.expected = fp_init(30, 0),
 	},
 	{
 		.link_rate = 810000,
 		.lane_count = 1,
 		.expected = fp_init(15, 0),
 	},
 	{
 		.link_rate = 540000,
 		.lane_count = 4,
 		.expected = fp_init(40, 0),
 	},
 	{
 		.link_rate = 540000,
 		.lane_count = 2,
 		.expected = fp_init(20, 0),
 	},
 	{
 		.link_rate = 540000,
 		.lane_count = 1,
 		.expected = fp_init(10, 0),
 	},
 	{
 		.link_rate = 270000,
 		.lane_count = 4,
 		.expected = fp_init(20, 0),
 	},
 	{
 		.link_rate = 270000,
 		.lane_count = 2,
 		.expected = fp_init(10, 0),
 	},
 	{
 		.link_rate = 270000,
 		.lane_count = 1,
 		.expected = fp_init(5, 0),
 	},
 	{
 		.link_rate = 162000,
 		.lane_count = 4,
 		.expected = fp_init(12, 0),
 	},
 	{
 		.link_rate = 162000,
 		.lane_count = 2,
 		.expected = fp_init(6, 0),
 	},
 	{
 		.link_rate = 162000,
 		.lane_count = 1,
 		.expected = fp_init(3, 0),
 	},
 };

 static void drm_test_dp_mst_calc_pbn_div(struct kunit *test)
 {
 	const struct drm_dp_mst_calc_pbn_div_test *params = test->param_value;
 	/* mgr->dev is only needed by drm_dbg_kms(), but it's not called for the test cases. */
 	struct drm_dp_mst_topology_mgr *mgr = test->priv;

 	KUNIT_EXPECT_EQ(test, drm_dp_get_vc_payload_bw(mgr, params->link_rate, params->lane_count).full,
 			params->expected.full);
 }

 static void dp_mst_calc_pbn_div_desc(const struct drm_dp_mst_calc_pbn_div_test *t, char *desc)
 {
 	sprintf(desc, "Link rate %d lane count %d", t->link_rate, t->lane_count);
 }

 KUNIT_ARRAY_PARAM(drm_dp_mst_calc_pbn_div, drm_dp_mst_calc_pbn_div_dp1_4_cases,
 		  dp_mst_calc_pbn_div_desc);

 static u8 data[] = { 0xff, 0x00, 0xdd };

 struct drm_dp_mst_sideband_msg_req_test {
 	const char *desc;
 	const struct drm_dp_sideband_msg_req_body in;
 };

 static const struct drm_dp_mst_sideband_msg_req_test drm_dp_mst_sideband_msg_req_cases[] = {
 	{
 		.desc = "DP_ENUM_PATH_RESOURCES with port number",
 		.in = {
 			.req_type = DP_ENUM_PATH_RESOURCES,
 			.u.port_num.port_number = 5,
 		},
 	},
 	{
 		.desc = "DP_POWER_UP_PHY with port number",
 		.in = {
 			.req_type = DP_POWER_UP_PHY,
 			.u.port_num.port_number = 5,
 		},
 	},
 	{
 		.desc = "DP_POWER_DOWN_PHY with port number",
 		.in = {
 			.req_type = DP_POWER_DOWN_PHY,
 			.u.port_num.port_number = 5,
 		},
 	},
 	{
 		.desc = "DP_ALLOCATE_PAYLOAD with SDP stream sinks",
 		.in = {
 			.req_type = DP_ALLOCATE_PAYLOAD,
 			.u.allocate_payload.number_sdp_streams = 3,
 			.u.allocate_payload.sdp_stream_sink = { 1, 2, 3 },
 		},
 	},
 	{
 		.desc = "DP_ALLOCATE_PAYLOAD with port number",
 		.in = {
 			.req_type = DP_ALLOCATE_PAYLOAD,
 			.u.allocate_payload.port_number = 0xf,
 		},
 	},
 	{
 		.desc = "DP_ALLOCATE_PAYLOAD with VCPI",
 		.in = {
 			.req_type = DP_ALLOCATE_PAYLOAD,
 			.u.allocate_payload.vcpi = 0x7f,
 		},
 	},
 	{
 		.desc = "DP_ALLOCATE_PAYLOAD with PBN",
 		.in = {
 			.req_type = DP_ALLOCATE_PAYLOAD,
 			.u.allocate_payload.pbn = U16_MAX,
 		},
 	},
 	{
 		.desc = "DP_QUERY_PAYLOAD with port number",
 		.in = {
 			.req_type = DP_QUERY_PAYLOAD,
 			.u.query_payload.port_number = 0xf,
 		},
 	},
 	{
 		.desc = "DP_QUERY_PAYLOAD with VCPI",
 		.in = {
 			.req_type = DP_QUERY_PAYLOAD,
 			.u.query_payload.vcpi = 0x7f,
 		},
 	},
 	{
 		.desc = "DP_REMOTE_DPCD_READ with port number",
 		.in = {
 			.req_type = DP_REMOTE_DPCD_READ,
 			.u.dpcd_read.port_number = 0xf,
 		},
 	},
 	{
 		.desc = "DP_REMOTE_DPCD_READ with DPCD address",
 		.in = {
 			.req_type = DP_REMOTE_DPCD_READ,
 			.u.dpcd_read.dpcd_address = 0xfedcb,
 		},
 	},
 	{
 		.desc = "DP_REMOTE_DPCD_READ with max number of bytes",
 		.in = {
 			.req_type = DP_REMOTE_DPCD_READ,
 			.u.dpcd_read.num_bytes = U8_MAX,
 		},
 	},
 	{
 		.desc = "DP_REMOTE_DPCD_WRITE with port number",
 		.in = {
 			.req_type = DP_REMOTE_DPCD_WRITE,
 			.u.dpcd_write.port_number = 0xf,
 		},
 	},
 	{
 		.desc = "DP_REMOTE_DPCD_WRITE with DPCD address",
 		.in = {
 			.req_type = DP_REMOTE_DPCD_WRITE,
 			.u.dpcd_write.dpcd_address = 0xfedcb,
 		},
 	},
 	{
 		.desc = "DP_REMOTE_DPCD_WRITE with data array",
 		.in = {
 			.req_type = DP_REMOTE_DPCD_WRITE,
 			.u.dpcd_write.num_bytes = ARRAY_SIZE(data),
 			.u.dpcd_write.bytes = data,
 		},
 	},
 	{
 		.desc = "DP_REMOTE_I2C_READ with port number",
 		.in = {
 			.req_type = DP_REMOTE_I2C_READ,
 			.u.i2c_read.port_number = 0xf,
 		},
 	},
 	{
 		.desc = "DP_REMOTE_I2C_READ with I2C device ID",
 		.in = {
 			.req_type = DP_REMOTE_I2C_READ,
 			.u.i2c_read.read_i2c_device_id = 0x7f,
 		},
 	},
 	{
 		.desc = "DP_REMOTE_I2C_READ with transactions array",
 		.in = {
 			.req_type = DP_REMOTE_I2C_READ,
 			.u.i2c_read.num_transactions = 3,
 			.u.i2c_read.num_bytes_read = ARRAY_SIZE(data) * 3,
 			.u.i2c_read.transactions = {
 				{ .bytes = data, .num_bytes = ARRAY_SIZE(data), .i2c_dev_id = 0x7f,
 				  .i2c_transaction_delay = 0xf, },
 				{ .bytes = data, .num_bytes = ARRAY_SIZE(data), .i2c_dev_id = 0x7e,
 				  .i2c_transaction_delay = 0xe, },
 				{ .bytes = data, .num_bytes = ARRAY_SIZE(data), .i2c_dev_id = 0x7d,
 				  .i2c_transaction_delay = 0xd, },
 			},
 		},
 	},
 	{
 		.desc = "DP_REMOTE_I2C_WRITE with port number",
 		.in = {
 			.req_type = DP_REMOTE_I2C_WRITE,
 			.u.i2c_write.port_number = 0xf,
 		},
 	},
 	{
 		.desc = "DP_REMOTE_I2C_WRITE with I2C device ID",
 		.in = {
 			.req_type = DP_REMOTE_I2C_WRITE,
 			.u.i2c_write.write_i2c_device_id = 0x7f,
 		},
 	},
 	{
 		.desc = "DP_REMOTE_I2C_WRITE with data array",
 		.in = {
 			.req_type = DP_REMOTE_I2C_WRITE,
 			.u.i2c_write.num_bytes = ARRAY_SIZE(data),
 			.u.i2c_write.bytes = data,
 		},
 	},
 	{
 		.desc = "DP_QUERY_STREAM_ENC_STATUS with stream ID",
 		.in = {
 			.req_type = DP_QUERY_STREAM_ENC_STATUS,
 			.u.enc_status.stream_id = 1,
 		},
 	},
 	{
 		.desc = "DP_QUERY_STREAM_ENC_STATUS with client ID",
 		.in = {
 			.req_type = DP_QUERY_STREAM_ENC_STATUS,
 			.u.enc_status.client_id = { 0x4f, 0x7f, 0xb4, 0x00, 0x8c, 0x0d, 0x67 },
 		},
 	},
 	{
 		.desc = "DP_QUERY_STREAM_ENC_STATUS with stream event",
 		.in = {
 			.req_type = DP_QUERY_STREAM_ENC_STATUS,
 			.u.enc_status.stream_event = 3,
 		},
 	},
 	{
 		.desc = "DP_QUERY_STREAM_ENC_STATUS with valid stream event",
 		.in = {
 			.req_type = DP_QUERY_STREAM_ENC_STATUS,
 			.u.enc_status.valid_stream_event = 0,
 		},
 	},
 	{
 		.desc = "DP_QUERY_STREAM_ENC_STATUS with stream behavior",
 		.in = {
 			.req_type = DP_QUERY_STREAM_ENC_STATUS,
 			.u.enc_status.stream_behavior = 3,
 		},
 	},
 	{
 		.desc = "DP_QUERY_STREAM_ENC_STATUS with a valid stream behavior",
 		.in = {
 			.req_type = DP_QUERY_STREAM_ENC_STATUS,
 			.u.enc_status.valid_stream_behavior = 1,
 		}
 	},
 };

 static bool
 sideband_msg_req_equal(const struct drm_dp_sideband_msg_req_body *in,
 		       const struct drm_dp_sideband_msg_req_body *out)
 {
 	const struct drm_dp_remote_i2c_read_tx *txin, *txout;
 	int i;

 	if (in->req_type != out->req_type)
 		return false;

 	switch (in->req_type) {
 	/*
 	 * Compare struct members manually for request types which can't be
 	 * compared simply using memcmp(). This is because said request types
 	 * contain pointers to other allocated structs
 	 */
 	case DP_REMOTE_I2C_READ:
 #define IN in->u.i2c_read
 #define OUT out->u.i2c_read
 		if (IN.num_bytes_read != OUT.num_bytes_read ||
 		    IN.num_transactions != OUT.num_transactions ||
 		    IN.port_number != OUT.port_number ||
 		    IN.read_i2c_device_id != OUT.read_i2c_device_id)
 			return false;

 		for (i = 0; i < IN.num_transactions; i++) {
 			txin = &IN.transactions[i];
 			txout = &OUT.transactions[i];

 			if (txin->i2c_dev_id != txout->i2c_dev_id ||
 			    txin->no_stop_bit != txout->no_stop_bit ||
 			    txin->num_bytes != txout->num_bytes ||
 			    txin->i2c_transaction_delay !=
 			    txout->i2c_transaction_delay)
 				return false;

 			if (memcmp(txin->bytes, txout->bytes,
 				   txin->num_bytes) != 0)
 				return false;
 		}
 		break;
 #undef IN
 #undef OUT

 	case DP_REMOTE_DPCD_WRITE:
 #define IN in->u.dpcd_write
 #define OUT out->u.dpcd_write
 		if (IN.dpcd_address != OUT.dpcd_address ||
 		    IN.num_bytes != OUT.num_bytes ||
 		    IN.port_number != OUT.port_number)
 			return false;

 		return memcmp(IN.bytes, OUT.bytes, IN.num_bytes) == 0;
 #undef IN
 #undef OUT

 	case DP_REMOTE_I2C_WRITE:
 #define IN in->u.i2c_write
 #define OUT out->u.i2c_write
 		if (IN.port_number != OUT.port_number ||
 		    IN.write_i2c_device_id != OUT.write_i2c_device_id ||
 		    IN.num_bytes != OUT.num_bytes)
 			return false;

 		return memcmp(IN.bytes, OUT.bytes, IN.num_bytes) == 0;
 #undef IN
 #undef OUT

 	default:
 		return memcmp(in, out, sizeof(*in)) == 0;
 	}

 	return true;
 }

 static void drm_test_dp_mst_msg_printf(struct drm_printer *p, struct va_format *vaf)
 {
 	struct kunit *test = p->arg;

 	kunit_err(test, "%pV", vaf);
 }

 static void drm_test_dp_mst_sideband_msg_req_decode(struct kunit *test)
 {
 	const struct drm_dp_mst_sideband_msg_req_test *params = test->param_value;
 	const struct drm_dp_sideband_msg_req_body *in = &params->in;
 	struct drm_dp_sideband_msg_req_body *out;
 	struct drm_dp_sideband_msg_tx *txmsg;
 	struct drm_printer p = {
 		.printfn = drm_test_dp_mst_msg_printf,
 		.arg = test
 	};
 	int i;

 	out = kunit_kzalloc(test, sizeof(*out), GFP_KERNEL);
 	KUNIT_ASSERT_NOT_NULL(test, out);

 	txmsg = kunit_kzalloc(test, sizeof(*txmsg), GFP_KERNEL);
 	KUNIT_ASSERT_NOT_NULL(test, txmsg);

 	drm_dp_encode_sideband_req(in, txmsg);
 	KUNIT_EXPECT_GE_MSG(test, drm_dp_decode_sideband_req(txmsg, out), 0,
 			    "Failed to decode sideband request");

 	if (!sideband_msg_req_equal(in, out)) {
 		KUNIT_FAIL(test, "Encode/decode failed");
 		kunit_err(test, "Expected:");
 		drm_dp_dump_sideband_msg_req_body(in, 1, &p);
 		kunit_err(test, "Got:");
 		drm_dp_dump_sideband_msg_req_body(out, 1, &p);
 	}

 	switch (in->req_type) {
 	case DP_REMOTE_DPCD_WRITE:
 		kfree(out->u.dpcd_write.bytes);
 		break;
 	case DP_REMOTE_I2C_READ:
 		for (i = 0; i < out->u.i2c_read.num_transactions; i++)
 			kfree(out->u.i2c_read.transactions[i].bytes);
 		break;
 	case DP_REMOTE_I2C_WRITE:
 		kfree(out->u.i2c_write.bytes);
 		break;
 	}
 }

 static void
 drm_dp_mst_sideband_msg_req_desc(const struct drm_dp_mst_sideband_msg_req_test *t, char *desc)
 {
 	strcpy(desc, t->desc);
 }

 KUNIT_ARRAY_PARAM(drm_dp_mst_sideband_msg_req, drm_dp_mst_sideband_msg_req_cases,
 		  drm_dp_mst_sideband_msg_req_desc);

 static struct kunit_case drm_dp_mst_helper_tests[] = {
 	KUNIT_CASE_PARAM(drm_test_dp_mst_calc_pbn_mode, drm_dp_mst_calc_pbn_mode_gen_params),
 	KUNIT_CASE_PARAM(drm_test_dp_mst_calc_pbn_div, drm_dp_mst_calc_pbn_div_gen_params),
 	KUNIT_CASE_PARAM(drm_test_dp_mst_sideband_msg_req_decode,
 			 drm_dp_mst_sideband_msg_req_gen_params),
 	{ }
 };

 static int drm_dp_mst_helper_tests_init(struct kunit *test)
 {
 	struct drm_dp_mst_topology_mgr *mgr;

 	mgr = kunit_kzalloc(test, sizeof(*mgr), GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, mgr);

 	test->priv = mgr;

 	return 0;
 }

 static struct kunit_suite drm_dp_mst_helper_test_suite = {
 	.name = "drm_dp_mst_helper",
 	.init = drm_dp_mst_helper_tests_init,
 	.test_cases = drm_dp_mst_helper_tests,
 };

 kunit_test_suite(drm_dp_mst_helper_test_suite);

 MODULE_DESCRIPTION("Test cases for the DRM DP MST helpers");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Test cases for the DRM DP MST helpers
	*
	* Copyright (c) 2022 Maíra Canal <mairacanal@riseup.net>
	*/

	#include <kunit/test.h>

	#include <drm/display/drm_dp_mst_helper.h>
	#include <drm/drm_print.h>

	#include "../display/drm_dp_mst_topology_internal.h"

	struct drm_dp_mst_calc_pbn_mode_test {
	const int clock;
	const int bpp;
	const bool dsc;
	const int expected;
	};

	static const struct drm_dp_mst_calc_pbn_mode_test drm_dp_mst_calc_pbn_mode_cases[] = {
	{
	.clock = 154000,
	.bpp = 30,
	.dsc = false,
	.expected = 689
	},
	{
	.clock = 234000,
	.bpp = 30,
	.dsc = false,
	.expected = 1047
	},
	{
	.clock = 297000,
	.bpp = 24,
	.dsc = false,
	.expected = 1063
	},
	{
	.clock = 332880,
	.bpp = 24,
	.dsc = true,
	.expected = 1191
	},
	{
	.clock = 324540,
	.bpp = 24,
	.dsc = true,
	.expected = 1161
	},
	};

	static void drm_test_dp_mst_calc_pbn_mode(struct kunit *test)
	{
	const struct drm_dp_mst_calc_pbn_mode_test *params = test->param_value;

	KUNIT_EXPECT_EQ(test, drm_dp_calc_pbn_mode(params->clock, params->bpp << 4),
	params->expected);
	}

	static void dp_mst_calc_pbn_mode_desc(const struct drm_dp_mst_calc_pbn_mode_test t, char desc)
	{
	sprintf(desc, "Clock %d BPP %d DSC %s", t->clock, t->bpp, t->dsc ? "enabled" : "disabled");
	}

	KUNIT_ARRAY_PARAM(drm_dp_mst_calc_pbn_mode, drm_dp_mst_calc_pbn_mode_cases,
	dp_mst_calc_pbn_mode_desc);

	struct drm_dp_mst_calc_pbn_div_test {
	int link_rate;
	int lane_count;
	fixed20_12 expected;
	};

	#define fp_init(__int, __frac) { \
	.full = (__int) * (1 << 12) + \
	(__frac) * (1 << 12) / 100000 \
	}

	static const struct drm_dp_mst_calc_pbn_div_test drm_dp_mst_calc_pbn_div_dp1_4_cases[] = {
	/*
	* UHBR rates (DP Standard v2.1 2.7.6.3, specifying the rounded to
	* closest value to 2 decimal places):
	* .expected = .link_rate * .lane_count * 0.9671 / 8 / 54 / 100
	* DP1.4 rates (DP Standard v2.1 2.6.4.2):
	* .expected = .link_rate * .lane_count * 0.8000 / 8 / 54 / 100
	*
	* truncated to 5 decimal places.
	*/
	{
	.link_rate = 2000000,
	.lane_count = 4,
	.expected = fp_init(179, 9259), /* 179.09259 */
	},
	{
	.link_rate = 2000000,
	.lane_count = 2,
	.expected = fp_init(89, 54629),
	},
	{
	.link_rate = 2000000,
	.lane_count = 1,
	.expected = fp_init(44, 77314),
	},
	{
	.link_rate = 1350000,
	.lane_count = 4,
	.expected = fp_init(120, 88750),
	},
	{
	.link_rate = 1350000,
	.lane_count = 2,
	.expected = fp_init(60, 44375),
	},
	{
	.link_rate = 1350000,
	.lane_count = 1,
	.expected = fp_init(30, 22187),
	},
	{
	.link_rate = 1000000,
	.lane_count = 4,
	.expected = fp_init(89, 54629),
	},
	{
	.link_rate = 1000000,
	.lane_count = 2,
	.expected = fp_init(44, 77314),
	},
	{
	.link_rate = 1000000,
	.lane_count = 1,
	.expected = fp_init(22, 38657),
	},
	{
	.link_rate = 810000,
	.lane_count = 4,
	.expected = fp_init(60, 0),
	},
	{
	.link_rate = 810000,
	.lane_count = 2,
	.expected = fp_init(30, 0),
	},
	{
	.link_rate = 810000,
	.lane_count = 1,
	.expected = fp_init(15, 0),
	},
	{
	.link_rate = 540000,
	.lane_count = 4,
	.expected = fp_init(40, 0),
	},
	{
	.link_rate = 540000,
	.lane_count = 2,
	.expected = fp_init(20, 0),
	},
	{
	.link_rate = 540000,
	.lane_count = 1,
	.expected = fp_init(10, 0),
	},
	{
	.link_rate = 270000,
	.lane_count = 4,
	.expected = fp_init(20, 0),
	},
	{
	.link_rate = 270000,
	.lane_count = 2,
	.expected = fp_init(10, 0),
	},
	{
	.link_rate = 270000,
	.lane_count = 1,
	.expected = fp_init(5, 0),
	},
	{
	.link_rate = 162000,
	.lane_count = 4,
	.expected = fp_init(12, 0),
	},
	{
	.link_rate = 162000,
	.lane_count = 2,
	.expected = fp_init(6, 0),
	},
	{
	.link_rate = 162000,
	.lane_count = 1,
	.expected = fp_init(3, 0),
	},
	};

	static void drm_test_dp_mst_calc_pbn_div(struct kunit *test)
	{
	const struct drm_dp_mst_calc_pbn_div_test *params = test->param_value;
	/* mgr->dev is only needed by drm_dbg_kms(), but it's not called for the test cases. */
	struct drm_dp_mst_topology_mgr *mgr = test->priv;

	KUNIT_EXPECT_EQ(test, drm_dp_get_vc_payload_bw(mgr, params->link_rate, params->lane_count).full,
	params->expected.full);
	}

	static void dp_mst_calc_pbn_div_desc(const struct drm_dp_mst_calc_pbn_div_test t, char desc)
	{
	sprintf(desc, "Link rate %d lane count %d", t->link_rate, t->lane_count);
	}

	KUNIT_ARRAY_PARAM(drm_dp_mst_calc_pbn_div, drm_dp_mst_calc_pbn_div_dp1_4_cases,
	dp_mst_calc_pbn_div_desc);

	static u8 data[] = { 0xff, 0x00, 0xdd };

	struct drm_dp_mst_sideband_msg_req_test {
	const char *desc;
	const struct drm_dp_sideband_msg_req_body in;
	};

	static const struct drm_dp_mst_sideband_msg_req_test drm_dp_mst_sideband_msg_req_cases[] = {
	{
	.desc = "DP_ENUM_PATH_RESOURCES with port number",
	.in = {
	.req_type = DP_ENUM_PATH_RESOURCES,
	.u.port_num.port_number = 5,
	},
	},
	{
	.desc = "DP_POWER_UP_PHY with port number",
	.in = {
	.req_type = DP_POWER_UP_PHY,
	.u.port_num.port_number = 5,
	},
	},
	{
	.desc = "DP_POWER_DOWN_PHY with port number",
	.in = {
	.req_type = DP_POWER_DOWN_PHY,
	.u.port_num.port_number = 5,
	},
	},
	{
	.desc = "DP_ALLOCATE_PAYLOAD with SDP stream sinks",
	.in = {
	.req_type = DP_ALLOCATE_PAYLOAD,
	.u.allocate_payload.number_sdp_streams = 3,
	.u.allocate_payload.sdp_stream_sink = { 1, 2, 3 },
	},
	},
	{
	.desc = "DP_ALLOCATE_PAYLOAD with port number",
	.in = {
	.req_type = DP_ALLOCATE_PAYLOAD,
	.u.allocate_payload.port_number = 0xf,
	},
	},
	{
	.desc = "DP_ALLOCATE_PAYLOAD with VCPI",
	.in = {
	.req_type = DP_ALLOCATE_PAYLOAD,
	.u.allocate_payload.vcpi = 0x7f,
	},
	},
	{
	.desc = "DP_ALLOCATE_PAYLOAD with PBN",
	.in = {
	.req_type = DP_ALLOCATE_PAYLOAD,
	.u.allocate_payload.pbn = U16_MAX,
	},
	},
	{
	.desc = "DP_QUERY_PAYLOAD with port number",
	.in = {
	.req_type = DP_QUERY_PAYLOAD,
	.u.query_payload.port_number = 0xf,
	},
	},
	{
	.desc = "DP_QUERY_PAYLOAD with VCPI",
	.in = {
	.req_type = DP_QUERY_PAYLOAD,
	.u.query_payload.vcpi = 0x7f,
	},
	},
	{
	.desc = "DP_REMOTE_DPCD_READ with port number",
	.in = {
	.req_type = DP_REMOTE_DPCD_READ,
	.u.dpcd_read.port_number = 0xf,
	},
	},
	{
	.desc = "DP_REMOTE_DPCD_READ with DPCD address",
	.in = {
	.req_type = DP_REMOTE_DPCD_READ,
	.u.dpcd_read.dpcd_address = 0xfedcb,
	},
	},
	{
	.desc = "DP_REMOTE_DPCD_READ with max number of bytes",
	.in = {
	.req_type = DP_REMOTE_DPCD_READ,
	.u.dpcd_read.num_bytes = U8_MAX,
	},
	},
	{
	.desc = "DP_REMOTE_DPCD_WRITE with port number",
	.in = {
	.req_type = DP_REMOTE_DPCD_WRITE,
	.u.dpcd_write.port_number = 0xf,
	},
	},
	{
	.desc = "DP_REMOTE_DPCD_WRITE with DPCD address",
	.in = {
	.req_type = DP_REMOTE_DPCD_WRITE,
	.u.dpcd_write.dpcd_address = 0xfedcb,
	},
	},
	{
	.desc = "DP_REMOTE_DPCD_WRITE with data array",
	.in = {
	.req_type = DP_REMOTE_DPCD_WRITE,
	.u.dpcd_write.num_bytes = ARRAY_SIZE(data),
	.u.dpcd_write.bytes = data,
	},
	},
	{
	.desc = "DP_REMOTE_I2C_READ with port number",
	.in = {
	.req_type = DP_REMOTE_I2C_READ,
	.u.i2c_read.port_number = 0xf,
	},
	},
	{
	.desc = "DP_REMOTE_I2C_READ with I2C device ID",
	.in = {
	.req_type = DP_REMOTE_I2C_READ,
	.u.i2c_read.read_i2c_device_id = 0x7f,
	},
	},
	{
	.desc = "DP_REMOTE_I2C_READ with transactions array",
	.in = {
	.req_type = DP_REMOTE_I2C_READ,
	.u.i2c_read.num_transactions = 3,
	.u.i2c_read.num_bytes_read = ARRAY_SIZE(data) * 3,
	.u.i2c_read.transactions = {
	{ .bytes = data, .num_bytes = ARRAY_SIZE(data), .i2c_dev_id = 0x7f,
	.i2c_transaction_delay = 0xf, },
	{ .bytes = data, .num_bytes = ARRAY_SIZE(data), .i2c_dev_id = 0x7e,
	.i2c_transaction_delay = 0xe, },
	{ .bytes = data, .num_bytes = ARRAY_SIZE(data), .i2c_dev_id = 0x7d,
	.i2c_transaction_delay = 0xd, },
	},
	},
	},
	{
	.desc = "DP_REMOTE_I2C_WRITE with port number",
	.in = {
	.req_type = DP_REMOTE_I2C_WRITE,
	.u.i2c_write.port_number = 0xf,
	},
	},
	{
	.desc = "DP_REMOTE_I2C_WRITE with I2C device ID",
	.in = {
	.req_type = DP_REMOTE_I2C_WRITE,
	.u.i2c_write.write_i2c_device_id = 0x7f,
	},
	},
	{
	.desc = "DP_REMOTE_I2C_WRITE with data array",
	.in = {
	.req_type = DP_REMOTE_I2C_WRITE,
	.u.i2c_write.num_bytes = ARRAY_SIZE(data),
	.u.i2c_write.bytes = data,
	},
	},
	{
	.desc = "DP_QUERY_STREAM_ENC_STATUS with stream ID",
	.in = {
	.req_type = DP_QUERY_STREAM_ENC_STATUS,
	.u.enc_status.stream_id = 1,
	},
	},
	{
	.desc = "DP_QUERY_STREAM_ENC_STATUS with client ID",
	.in = {
	.req_type = DP_QUERY_STREAM_ENC_STATUS,
	.u.enc_status.client_id = { 0x4f, 0x7f, 0xb4, 0x00, 0x8c, 0x0d, 0x67 },
	},
	},
	{
	.desc = "DP_QUERY_STREAM_ENC_STATUS with stream event",
	.in = {
	.req_type = DP_QUERY_STREAM_ENC_STATUS,
	.u.enc_status.stream_event = 3,
	},
	},
	{
	.desc = "DP_QUERY_STREAM_ENC_STATUS with valid stream event",
	.in = {
	.req_type = DP_QUERY_STREAM_ENC_STATUS,
	.u.enc_status.valid_stream_event = 0,
	},
	},
	{
	.desc = "DP_QUERY_STREAM_ENC_STATUS with stream behavior",
	.in = {
	.req_type = DP_QUERY_STREAM_ENC_STATUS,
	.u.enc_status.stream_behavior = 3,
	},
	},
	{
	.desc = "DP_QUERY_STREAM_ENC_STATUS with a valid stream behavior",
	.in = {
	.req_type = DP_QUERY_STREAM_ENC_STATUS,
	.u.enc_status.valid_stream_behavior = 1,
	}
	},
	};

	static bool
	sideband_msg_req_equal(const struct drm_dp_sideband_msg_req_body *in,
	const struct drm_dp_sideband_msg_req_body *out)
	{
	const struct drm_dp_remote_i2c_read_tx txin, txout;
	int i;

	if (in->req_type != out->req_type)
	return false;

	switch (in->req_type) {
	/*
	* Compare struct members manually for request types which can't be
	* compared simply using memcmp(). This is because said request types
	* contain pointers to other allocated structs
	*/
	case DP_REMOTE_I2C_READ:
	#define IN in->u.i2c_read
	#define OUT out->u.i2c_read
	if (IN.num_bytes_read != OUT.num_bytes_read \|\|
	IN.num_transactions != OUT.num_transactions \|\|
	IN.port_number != OUT.port_number \|\|
	IN.read_i2c_device_id != OUT.read_i2c_device_id)
	return false;

	for (i = 0; i < IN.num_transactions; i++) {
	txin = &IN.transactions[i];
	txout = &OUT.transactions[i];

	if (txin->i2c_dev_id != txout->i2c_dev_id \|\|
	txin->no_stop_bit != txout->no_stop_bit \|\|
	txin->num_bytes != txout->num_bytes \|\|
	txin->i2c_transaction_delay !=
	txout->i2c_transaction_delay)
	return false;

	if (memcmp(txin->bytes, txout->bytes,
	txin->num_bytes) != 0)
	return false;
	}
	break;
	#undef IN
	#undef OUT

	case DP_REMOTE_DPCD_WRITE:
	#define IN in->u.dpcd_write
	#define OUT out->u.dpcd_write
	if (IN.dpcd_address != OUT.dpcd_address \|\|
	IN.num_bytes != OUT.num_bytes \|\|
	IN.port_number != OUT.port_number)
	return false;

	return memcmp(IN.bytes, OUT.bytes, IN.num_bytes) == 0;
	#undef IN
	#undef OUT

	case DP_REMOTE_I2C_WRITE:
	#define IN in->u.i2c_write
	#define OUT out->u.i2c_write
	if (IN.port_number != OUT.port_number \|\|
	IN.write_i2c_device_id != OUT.write_i2c_device_id \|\|
	IN.num_bytes != OUT.num_bytes)
	return false;

	return memcmp(IN.bytes, OUT.bytes, IN.num_bytes) == 0;
	#undef IN
	#undef OUT

	default:
	return memcmp(in, out, sizeof(*in)) == 0;
	}

	return true;
	}

	static void drm_test_dp_mst_msg_printf(struct drm_printer p, struct va_format vaf)
	{
	struct kunit *test = p->arg;

	kunit_err(test, "%pV", vaf);
	}

	static void drm_test_dp_mst_sideband_msg_req_decode(struct kunit *test)
	{
	const struct drm_dp_mst_sideband_msg_req_test *params = test->param_value;
	const struct drm_dp_sideband_msg_req_body *in = &params->in;
	struct drm_dp_sideband_msg_req_body *out;
	struct drm_dp_sideband_msg_tx *txmsg;
	struct drm_printer p = {
	.printfn = drm_test_dp_mst_msg_printf,
	.arg = test
	};
	int i;

	out = kunit_kzalloc(test, sizeof(*out), GFP_KERNEL);
	KUNIT_ASSERT_NOT_NULL(test, out);

	txmsg = kunit_kzalloc(test, sizeof(*txmsg), GFP_KERNEL);
	KUNIT_ASSERT_NOT_NULL(test, txmsg);

	drm_dp_encode_sideband_req(in, txmsg);
	KUNIT_EXPECT_GE_MSG(test, drm_dp_decode_sideband_req(txmsg, out), 0,
	"Failed to decode sideband request");

	if (!sideband_msg_req_equal(in, out)) {
	KUNIT_FAIL(test, "Encode/decode failed");
	kunit_err(test, "Expected:");
	drm_dp_dump_sideband_msg_req_body(in, 1, &p);
	kunit_err(test, "Got:");
	drm_dp_dump_sideband_msg_req_body(out, 1, &p);
	}

	switch (in->req_type) {
	case DP_REMOTE_DPCD_WRITE:
	kfree(out->u.dpcd_write.bytes);
	break;
	case DP_REMOTE_I2C_READ:
	for (i = 0; i < out->u.i2c_read.num_transactions; i++)
	kfree(out->u.i2c_read.transactions[i].bytes);
	break;
	case DP_REMOTE_I2C_WRITE:
	kfree(out->u.i2c_write.bytes);
	break;
	}
	}

	static void
	drm_dp_mst_sideband_msg_req_desc(const struct drm_dp_mst_sideband_msg_req_test t, char desc)
	{
	strcpy(desc, t->desc);
	}

	KUNIT_ARRAY_PARAM(drm_dp_mst_sideband_msg_req, drm_dp_mst_sideband_msg_req_cases,
	drm_dp_mst_sideband_msg_req_desc);

	static struct kunit_case drm_dp_mst_helper_tests[] = {
	KUNIT_CASE_PARAM(drm_test_dp_mst_calc_pbn_mode, drm_dp_mst_calc_pbn_mode_gen_params),
	KUNIT_CASE_PARAM(drm_test_dp_mst_calc_pbn_div, drm_dp_mst_calc_pbn_div_gen_params),
	KUNIT_CASE_PARAM(drm_test_dp_mst_sideband_msg_req_decode,
	drm_dp_mst_sideband_msg_req_gen_params),
	{ }
	};

	static int drm_dp_mst_helper_tests_init(struct kunit *test)
	{
	struct drm_dp_mst_topology_mgr *mgr;

	mgr = kunit_kzalloc(test, sizeof(*mgr), GFP_KERNEL);
	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, mgr);

	test->priv = mgr;

	return 0;
	}

	static struct kunit_suite drm_dp_mst_helper_test_suite = {
	.name = "drm_dp_mst_helper",
	.init = drm_dp_mst_helper_tests_init,
	.test_cases = drm_dp_mst_helper_tests,
	};

	kunit_test_suite(drm_dp_mst_helper_test_suite);

	MODULE_DESCRIPTION("Test cases for the DRM DP MST helpers");
	MODULE_LICENSE("GPL");