[Intel-gfx] [PATCH v2 03/11] drm/dp_mst: Add kunit tests for drm_dp_get_vc_payload_bw()

[Ville Syrjälä]

On Thu, Nov 16, 2023 at 03:18:33PM +0200, Imre Deak wrote:
> Add kunit test cases for drm_dp_get_vc_payload_bw() with all the DP1.4
> and UHBR link configurations.
> 
> Cc: Lyude Paul <lyude at redhat.com>
> Cc: dri-devel at lists.freedesktop.org
> Signed-off-by: Imre Deak <imre.deak at intel.com>
> ---
>  .../gpu/drm/tests/drm_dp_mst_helper_test.c    | 145 ++++++++++++++++++
>  1 file changed, 145 insertions(+)
> 
> diff --git a/drivers/gpu/drm/tests/drm_dp_mst_helper_test.c b/drivers/gpu/drm/tests/drm_dp_mst_helper_test.c
> index e3c818dfc0e6d..cafb463124f71 100644
> --- a/drivers/gpu/drm/tests/drm_dp_mst_helper_test.c
> +++ b/drivers/gpu/drm/tests/drm_dp_mst_helper_test.c
> @@ -68,6 +68,150 @@ static void dp_mst_calc_pbn_mode_desc(const struct drm_dp_mst_calc_pbn_mode_test
>  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[] = {
> +	/*
> +	 * DP1.4 rates:
> +	 * .expected = .link_rate * .lane_count * 0.8000 / 8 / 54 / 100
> +	 * UHBR rates:
> +	 * .expected = .link_rate * .lane_count * 0.9671 / 8 / 54 / 100
> +	 * truncated to 5 decimal places.
> +	 */
> +	{
> +		.link_rate = 162000,
> +		.lane_count = 1,
> +		.expected = fp_init(3, 0),
> +	},

Would be nice to sort this to match the tables in the spec.
A bit hard to do a quick visual comparison now.

> +	{
> +		.link_rate = 162000,
> +		.lane_count = 2,
> +		.expected = fp_init(6, 0),
> +	},
> +	{
> +		.link_rate = 162000,
> +		.lane_count = 4,
> +		.expected = fp_init(12, 0),
> +	},
> +	{
> +		.link_rate = 270000,
> +		.lane_count = 1,
> +		.expected = fp_init(5, 0),
> +	},
> +	{
> +		.link_rate = 270000,
> +		.lane_count = 2,
> +		.expected = fp_init(10, 0),
> +	},
> +	{
> +		.link_rate = 270000,
> +		.lane_count = 4,
> +		.expected = fp_init(20, 0),
> +	},
> +	{
> +		.link_rate = 540000,
> +		.lane_count = 1,
> +		.expected = fp_init(10, 0),
> +	},
> +	{
> +		.link_rate = 540000,
> +		.lane_count = 2,
> +		.expected = fp_init(20, 0),
> +	},
> +	{
> +		.link_rate = 540000,
> +		.lane_count = 4,
> +		.expected = fp_init(40, 0),
> +	},
> +	{
> +		.link_rate = 810000,
> +		.lane_count = 1,
> +		.expected = fp_init(15, 0),
> +	},
> +	{
> +		.link_rate = 810000,
> +		.lane_count = 2,
> +		.expected = fp_init(30, 0),
> +	},
> +	{
> +		.link_rate = 810000,
> +		.lane_count = 4,
> +		.expected = fp_init(60, 0),
> +	},
> +	{
> +		.link_rate = 1000000,
> +		.lane_count = 1,
> +		.expected = fp_init(22, 38657),
> +	},
> +	{
> +		.link_rate = 1000000,
> +		.lane_count = 2,
> +		.expected = fp_init(44, 77314),
> +	},
> +	{
> +		.link_rate = 1000000,
> +		.lane_count = 4,
> +		.expected = fp_init(89, 54629),
> +	},
> +	{
> +		.link_rate = 1350000,
> +		.lane_count = 1,
> +		.expected = fp_init(30, 22187),
> +	},
> +	{
> +		.link_rate = 1350000,
> +		.lane_count = 2,
> +		.expected = fp_init(60, 44375),
> +	},
> +	{
> +		.link_rate = 1350000,
> +		.lane_count = 4,
> +		.expected = fp_init(120, 88750),
> +	},
> +	{
> +		.link_rate = 2000000,
> +		.lane_count = 1,
> +		.expected = fp_init(44, 77314),
> +	},
> +	{
> +		.link_rate = 2000000,
> +		.lane_count = 2,
> +		.expected = fp_init(89, 54629),
> +	},
> +	{
> +		.link_rate = 2000000,
> +		.lane_count = 4,
> +		.expected = fp_init(179,  9259),  /* 179.09259 */
> +	},
> +};
> +
> +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 = {};
> +
> +	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 {
> @@ -416,6 +560,7 @@ KUNIT_ARRAY_PARAM(drm_dp_mst_sideband_msg_req, drm_dp_mst_sideband_msg_req_cases
>  
>  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),
>  	{ }
> -- 
> 2.39.2

-- 
Ville Syrjälä
Intel