Re: [PATCH v2 04/27] drm/dp_mst: Move test_calc_pbn_mode() into an actual selftest

[Sean Paul <sean@poorly.run>]

On Tue, Sep 03, 2019 at 04:45:42PM -0400, Lyude Paul wrote:
> Yes, apparently we've been testing this for every single driver load for
> quite a long time now. At least that means our PBN calculation is solid!
> 
> Anyway, introduce self tests for MST and move this into there.
> 
> Cc: Juston Li <juston.li@intel.com>
> Cc: Imre Deak <imre.deak@intel.com>
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Cc: Harry Wentland <hwentlan@amd.com>
> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> Signed-off-by: Lyude Paul <lyude@redhat.com>

Reviewed-by: Sean Paul <sean@poorly.run>

> ---
>  drivers/gpu/drm/drm_dp_mst_topology.c         | 27 ---------------
>  drivers/gpu/drm/selftests/Makefile            |  2 +-
>  .../gpu/drm/selftests/drm_modeset_selftests.h |  1 +
>  .../drm/selftests/test-drm_dp_mst_helper.c    | 34 +++++++++++++++++++
>  .../drm/selftests/test-drm_modeset_common.h   |  1 +
>  5 files changed, 37 insertions(+), 28 deletions(-)
>  create mode 100644 drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
> 
> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
> index 738f260d4b15..6f7f449ca12b 100644
> --- a/drivers/gpu/drm/drm_dp_mst_topology.c
> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c
> @@ -47,7 +47,6 @@
>   */
>  static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
>  				  char *buf);
> -static int test_calc_pbn_mode(void);
>  
>  static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port);
>  
> @@ -3561,30 +3560,6 @@ int drm_dp_calc_pbn_mode(int clock, int bpp)
>  }
>  EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
>  
> -static int test_calc_pbn_mode(void)
> -{
> -	int ret;
> -	ret = drm_dp_calc_pbn_mode(154000, 30);
> -	if (ret != 689) {
> -		DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
> -				154000, 30, 689, ret);
> -		return -EINVAL;
> -	}
> -	ret = drm_dp_calc_pbn_mode(234000, 30);
> -	if (ret != 1047) {
> -		DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
> -				234000, 30, 1047, ret);
> -		return -EINVAL;
> -	}
> -	ret = drm_dp_calc_pbn_mode(297000, 24);
> -	if (ret != 1063) {
> -		DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
> -				297000, 24, 1063, ret);
> -		return -EINVAL;
> -	}
> -	return 0;
> -}
> -
>  /* we want to kick the TX after we've ack the up/down IRQs. */
>  static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
>  {
> @@ -4033,8 +4008,6 @@ int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
>  	if (!mgr->proposed_vcpis)
>  		return -ENOMEM;
>  	set_bit(0, &mgr->payload_mask);
> -	if (test_calc_pbn_mode() < 0)
> -		DRM_ERROR("MST PBN self-test failed\n");
>  
>  	mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
>  	if (mst_state == NULL)
> diff --git a/drivers/gpu/drm/selftests/Makefile b/drivers/gpu/drm/selftests/Makefile
> index aae88f8a016c..d2137342b371 100644
> --- a/drivers/gpu/drm/selftests/Makefile
> +++ b/drivers/gpu/drm/selftests/Makefile
> @@ -1,6 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0-only
>  test-drm_modeset-y := test-drm_modeset_common.o test-drm_plane_helper.o \
>                        test-drm_format.o test-drm_framebuffer.o \
> -		      test-drm_damage_helper.o
> +		      test-drm_damage_helper.o test-drm_dp_mst_helper.o
>  
>  obj-$(CONFIG_DRM_DEBUG_SELFTEST) += test-drm_mm.o test-drm_modeset.o test-drm_cmdline_parser.o
> diff --git a/drivers/gpu/drm/selftests/drm_modeset_selftests.h b/drivers/gpu/drm/selftests/drm_modeset_selftests.h
> index 464753746013..dec3ee3ec96f 100644
> --- a/drivers/gpu/drm/selftests/drm_modeset_selftests.h
> +++ b/drivers/gpu/drm/selftests/drm_modeset_selftests.h
> @@ -32,3 +32,4 @@ selftest(damage_iter_damage_one_intersect, igt_damage_iter_damage_one_intersect)
>  selftest(damage_iter_damage_one_outside, igt_damage_iter_damage_one_outside)
>  selftest(damage_iter_damage_src_moved, igt_damage_iter_damage_src_moved)
>  selftest(damage_iter_damage_not_visible, igt_damage_iter_damage_not_visible)
> +selftest(dp_mst_calc_pbn_mode, igt_dp_mst_calc_pbn_mode)
> diff --git a/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c b/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
> new file mode 100644
> index 000000000000..9baa5171988d
> --- /dev/null
> +++ b/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
> @@ -0,0 +1,34 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Test cases for for the DRM DP MST helpers
> + */
> +
> +#include <drm/drm_dp_mst_helper.h>
> +#include <drm/drm_print.h>
> +
> +#include "test-drm_modeset_common.h"
> +
> +int igt_dp_mst_calc_pbn_mode(void *ignored)
> +{
> +	int pbn, i;
> +	const struct {
> +		int rate;
> +		int bpp;
> +		int expected;
> +	} test_params[] = {
> +		{ 154000, 30, 689 },
> +		{ 234000, 30, 1047 },
> +		{ 297000, 24, 1063 },
> +	};
> +
> +	for (i = 0; i < ARRAY_SIZE(test_params); i++) {
> +		pbn = drm_dp_calc_pbn_mode(test_params[i].rate,
> +					   test_params[i].bpp);
> +		FAIL(pbn != test_params[i].expected,
> +		     "Expected PBN %d for clock %d bpp %d, got %d\n",
> +		     test_params[i].expected, test_params[i].rate,
> +		     test_params[i].bpp, pbn);
> +	}
> +
> +	return 0;
> +}
> diff --git a/drivers/gpu/drm/selftests/test-drm_modeset_common.h b/drivers/gpu/drm/selftests/test-drm_modeset_common.h
> index 8c76f09c12d1..590bda35a683 100644
> --- a/drivers/gpu/drm/selftests/test-drm_modeset_common.h
> +++ b/drivers/gpu/drm/selftests/test-drm_modeset_common.h
> @@ -39,5 +39,6 @@ int igt_damage_iter_damage_one_intersect(void *ignored);
>  int igt_damage_iter_damage_one_outside(void *ignored);
>  int igt_damage_iter_damage_src_moved(void *ignored);
>  int igt_damage_iter_damage_not_visible(void *ignored);
> +int igt_dp_mst_calc_pbn_mode(void *ignored);
>  
>  #endif
> -- 
> 2.21.0
> 

-- 
Sean Paul, Software Engineer, Google / Chromium OS