Re: [PATCH i-g-t,v6 3/4] tests/intel/kms_dsc_helper: Add helper func()

[Karthik B S <karthik.b.s@intel.com>]

Hi Swati,

On 5/1/2026 12:39 AM, Swati Sharma wrote:

> Introduce check_dsc_joiner_constraints() to validate minimum pipe
> count, DSC slice requirements, and joiner support for DSC joiner
> scenarios.
>
> Update meson.build to link kms_joiner_helper.c into DSC-related
> tests so the new helper can call igt_is_joiner_supported_by_source().
>
> v2: -Avoid hardcoding min_pipes/min_slices, use enum values (Santhosh)
>
> Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
> ---
>   tests/intel/kms_dsc_helper.c | 54 ++++++++++++++++++++++++++++++++++++
>   tests/intel/kms_dsc_helper.h |  3 ++
>   tests/meson.build            | 17 ++++++++----
>   3 files changed, 68 insertions(+), 6 deletions(-)
>
> diff --git a/tests/intel/kms_dsc_helper.c b/tests/intel/kms_dsc_helper.c
> index 29b998c2f..63170af1e 100644
> --- a/tests/intel/kms_dsc_helper.c
> +++ b/tests/intel/kms_dsc_helper.c
> @@ -203,3 +203,57 @@ bool is_dsc_fractional_bpp_supported(int disp_ver, int drmfd, igt_output_t *outp
>   
>   	return true;
>   }
> +
> +bool check_dsc_joiner_constraints(int drm_fd,
> +                                  igt_output_t *output,
> +                                  int num_pipes,
> +                                  enum joined_pipes type)
> +{
> +	int min_pipes = 0, min_slices = 0;
> +
> +	if (!igt_is_joiner_supported_by_source(drm_fd, type))
> +		return false;
> +
> +	/*
> +	 * For joiner, 2 slices per pipe is used
> +	 * i.e. min_slices = 2 * min_pipes
> +	 */
> +	switch (type) {
> +	case JOINED_PIPES_BIG_JOINER:
> +		min_pipes = JOINED_PIPES_BIG_JOINER;
> +		min_slices = min_pipes * 2;
> +		break;
> +	case JOINED_PIPES_ULTRA_JOINER:
> +		min_pipes = JOINED_PIPES_ULTRA_JOINER;
> +		min_slices = min_pipes * 2;
> +		break;
> +	case JOINED_PIPES_NONE:
> +	case JOINED_PIPES_DEFAULT:
IMHO, since this helper can be potentially called other tests in the 
future, we should not call these as unsupported with DSC.
> +	default:
> +		igt_info("Unsupported joiner type: %s\n",
> +                          igt_get_joined_pipes_name(type));

There seem to be a bunch of indentation and styling issues checkpatch is 
throwing, please fix them.

Thanks and Regards,
Karthik.B.S
> +		return false;
> +	}
> +
> +	if (num_pipes < min_pipes) {
> +		igt_info("%s requires minimum %d pipes\n",
> +			  igt_get_joined_pipes_name(type), min_pipes);
> +		return false;
> +	}
> +
> +	if (igt_get_dsc_sink_max_slice_count(drm_fd, output->name) < min_slices) {
> +		igt_info("Output %s doesn't support minimum %d slice count for %s\n",
> +			  igt_output_name(output), min_slices,
> +			  igt_get_joined_pipes_name(type));
> +		return false;
> +	}
> +
> +	if (!igt_has_force_joiner_debugfs(drm_fd, output->name)) {
> +	    igt_info("Output %s doesn't support force_joiner debugfs for %s\n",
> +		      igt_output_name(output),
> +		      igt_get_joined_pipes_name(type));
> +		return false;
> +	}
> +
> +	return true;
> +}
> diff --git a/tests/intel/kms_dsc_helper.h b/tests/intel/kms_dsc_helper.h
> index ee419c849..e4c970447 100644
> --- a/tests/intel/kms_dsc_helper.h
> +++ b/tests/intel/kms_dsc_helper.h
> @@ -8,6 +8,7 @@
>   
>   #include "igt.h"
>   #include "igt_sysfs.h"
> +#include "kms_joiner_helper.h"
>   #include <errno.h>
>   #include <getopt.h>
>   #include <math.h>
> @@ -39,5 +40,7 @@ void force_dsc_fractional_bpp_enable(int drmfd, igt_output_t *output);
>   void save_force_dsc_fractional_bpp_en(int drmfd, igt_output_t *output);
>   void restore_force_dsc_fractional_bpp_en(void);
>   bool is_dsc_fractional_bpp_supported(int disp_ver, int drmfd, igt_output_t *output);
> +bool check_dsc_joiner_constraints(int drm_fd, igt_output_t *output, int num_pipes,
> +                                  enum joined_pipes type);
>   
>   #endif
> diff --git a/tests/meson.build b/tests/meson.build
> index 60cea3aa8..38a42bda6 100644
> --- a/tests/meson.build
> +++ b/tests/meson.build
> @@ -399,14 +399,19 @@ extra_sources = {
>   	'kms_chamelium_hpd': [ join_paths ('chamelium', 'kms_chamelium_helper.c') ],
>   	'kms_chamelium_sharpness_filter': [ join_paths ('chamelium', 'kms_chamelium_helper.c') ],
>   	'kms_dp_linktrain_fallback': [
> -           join_paths ('intel', 'kms_mst_helper.c'),
> -           join_paths ('intel', 'kms_dsc_helper.c') ],
> +          join_paths ('intel', 'kms_mst_helper.c'),
> +          join_paths ('intel', 'kms_dsc_helper.c'),
> +          join_paths ('intel', 'kms_joiner_helper.c') ],
>   	'kms_dp_link_training': [
> -           join_paths ('intel', 'kms_mst_helper.c'),
> -           join_paths ('intel', 'kms_joiner_helper.c') ],
> -	'kms_dsc': [ join_paths ('intel', 'kms_dsc_helper.c') ],
> +          join_paths ('intel', 'kms_mst_helper.c'),
> +          join_paths ('intel', 'kms_joiner_helper.c') ],
> +	'kms_dsc': [
> +          join_paths ('intel', 'kms_dsc_helper.c'),
> +          join_paths ('intel', 'kms_joiner_helper.c') ],
>   	'kms_joiner': [ join_paths ('intel', 'kms_joiner_helper.c') ],
> -	'kms_psr2_sf':  [ join_paths ('intel', 'kms_dsc_helper.c') ],
> +	'kms_psr2_sf': [
> +          join_paths ('intel', 'kms_dsc_helper.c'),
> +          join_paths ('intel', 'kms_joiner_helper.c') ],
>   }
>   
>   # Extra dependencies used on core and Intel drivers