[PATCH i-g-t 1/6] tests/intel/kms_mst_helper: add helper for MST-related functions

[Nautiyal, Ankit K]

On 2/11/2025 12:26 AM, Kunal Joshi wrote:
> Add helper to centralize commonly used MST-related logic.
> igt_find_all_mst_output_in_topology() enumerates MST outputs
> that share the same root connector id.
>
> v2: fix docs (Ankit)
>      change return type to int (Ankit)
>      split patch (Ankit)
>
> Cc: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
> Signed-off-by: Kunal Joshi <kunal1.joshi at intel.com>
> ---
>   tests/intel/kms_mst_helper.c | 49 ++++++++++++++++++++++++++++++++++++
>   tests/intel/kms_mst_helper.h | 15 +++++++++++
>   2 files changed, 64 insertions(+)
>   create mode 100644 tests/intel/kms_mst_helper.c
>   create mode 100644 tests/intel/kms_mst_helper.h
>
> diff --git a/tests/intel/kms_mst_helper.c b/tests/intel/kms_mst_helper.c
> new file mode 100644
> index 000000000..fb5aaab77
> --- /dev/null
> +++ b/tests/intel/kms_mst_helper.c
> @@ -0,0 +1,49 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2023 Intel Corporation

s/2023/2025


> + */
> +
> +#include "kms_mst_helper.h"
> +
> +/*
> + * @drm_fd: DRM file descriptor
> + * @display: pointer to #igt_display_t structure
> + * @output: target output
> + * @mst_outputs: filled with mst output of same toplogy as @output
> + * @num_mst_outputs: filled with count of mst outputs found in topology
> + *
> + * Iterates over all connected outputs and adds each DP MST
> + * output that shares the same MST connector ID as @output
> + * into @mst_outputs.
> + *
> + * Returns: 0 on success, -1 on failure

Just return the ERROR code.


> + */
> +int igt_find_all_mst_output_in_topology(int drm_fd, igt_display_t *display,
> +					 igt_output_t *output,
> +					 igt_output_t *mst_outputs[],
> +					 int *num_mst_outputs)
> +{
> +	int output_root_id, root_id;
> +	igt_output_t *connector_output;
> +
> +	if (!igt_check_output_is_dp_mst(output))
> +		return -1;

return -EINVAL


> +
> +	output_root_id = igt_get_dp_mst_connector_id(output);
> +	if (output_root_id == -EINVAL)
> +		return -1;

return -EINVAL


> +
> +	/*
> +	 * If output is MST, check all other connected output which shares
> +	 * same path and fill mst_outputs and num_mst_outputs
> +	 */
> +	for_each_connected_output(display, connector_output) {
> +		if (!igt_check_output_is_dp_mst(connector_output))
> +			continue;
> +
> +		root_id = igt_get_dp_mst_connector_id(connector_output);
> +		if (((*num_mst_outputs) < IGT_MAX_PIPES) && root_id == output_root_id)
> +			mst_outputs[(*num_mst_outputs)++] = connector_output;
> +	}
> +	return 0;
> +}
> diff --git a/tests/intel/kms_mst_helper.h b/tests/intel/kms_mst_helper.h
> new file mode 100644
> index 000000000..637ca696e
> --- /dev/null
> +++ b/tests/intel/kms_mst_helper.h
> @@ -0,0 +1,15 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2023 Intel Corporation

s/2023/2025


Regards,

Ankit

> + */
> +
> +#ifndef KMS_MST_HELPER_H
> +#define KMS_MST_HELPER_H
> +
> +#include "igt.h"
> +
> +int igt_find_all_mst_output_in_topology(int drm_fd, igt_display_t *display,
> +					 igt_output_t *output,
> +					 igt_output_t *mst_outputs[],
> +					 int *num_mst_outputs);
> +#endif