[PATCH i-g-t 1/3] tests/intel/kms_mst_helper: Add helper for MST-related functions

[Kunal Joshi <kunal1.joshi@intel.com>]

This patch introduces kms_mst_helper.c and kms_mst_helper.h
to centralize commonly used MST-related logic.
The new function igt_find_all_mst_output_in_topology()
enumerates MST outputs that share the same root connector,
simplifying code reuse across tests needing outputs on
same MST topology. The existing MST-related code in
kms_dp_linktrain_fallback.c is updated to use the new helper,
removing duplication. Additionally, meson.build is modified
to include kms_mst_helper.c in the build process.

Signed-off-by: Kunal Joshi <kunal1.joshi@intel.com>
---
 tests/intel/kms_dp_linktrain_fallback.c | 28 ++++---------------------
 tests/meson.build                       |  1 +
 2 files changed, 5 insertions(+), 24 deletions(-)

diff --git a/tests/intel/kms_dp_linktrain_fallback.c b/tests/intel/kms_dp_linktrain_fallback.c
index a05e2015f..b10946781 100644
--- a/tests/intel/kms_dp_linktrain_fallback.c
+++ b/tests/intel/kms_dp_linktrain_fallback.c
@@ -16,6 +16,7 @@
 #include <sys/types.h>
 
 #include "igt.h"
+#include "kms_mst_helper.h"
 
 /**
  * SUBTEST: dp-fallback
@@ -47,28 +48,6 @@ typedef int (*condition_check_fn)(int drm_fd, igt_output_t *output);
 
 IGT_TEST_DESCRIPTION("Test link training fallback");
 
-static void find_mst_outputs(int drm_fd, data_t *data,
-			     igt_output_t *output,
-			     igt_output_t *mst_outputs[],
-			     int *num_mst_outputs)
-{
-	int output_root_id, root_id;
-	igt_output_t *connector_output;
-
-	output_root_id = igt_get_dp_mst_connector_id(output);
-	/*
-	 * 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(&data->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;
-	}
-}
-
 static bool setup_mst_outputs(data_t *data, igt_output_t *mst_output[],
 			      int *output_count)
 {
@@ -83,8 +62,9 @@ static bool setup_mst_outputs(data_t *data, igt_output_t *mst_output[],
 		    traversed_mst_outputs[i] == data->output->config.connector->connector_id)
 			return false;
 
-	find_mst_outputs(data->drm_fd, data, data->output,
-			 mst_output, output_count);
+       igt_assert_f(igt_find_all_mst_output_in_topology(data->drm_fd, &data->display, data->output,
+							mst_output, output_count),
+		    "Unable to find mst outputs\n");
 
 	for (i = 0; i < *output_count; i++) {
 		output = mst_output[i];
diff --git a/tests/meson.build b/tests/meson.build
index 33dffad31..2cbd21c2a 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -367,6 +367,7 @@ extra_sources = {
 	'kms_chamelium_frames': [ join_paths ('chamelium', 'kms_chamelium_helper.c') ],
 	'kms_chamelium_hpd': [ join_paths ('chamelium', 'kms_chamelium_helper.c') ],
 	'kms_dsc': [ join_paths ('intel', 'kms_dsc_helper.c') ],
+	'kms_dp_linktrain_fallback': [join_paths ('intel', 'kms_mst_helper.c')],
 	'kms_psr2_sf':  [ join_paths ('intel', 'kms_dsc_helper.c') ],
 }
 
-- 
2.25.1