[PATCH i-g-t v1] lib/igt_kms: Backup connector modes before sorting

[Santhosh Reddy Guddati]

Backup connector modes before sorting to ensure the original mode
is not changed if the joiner is not found.This will skip updating
connector->mode[0] if joiner is not available.

Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13287
Signed-off-by: Santhosh Reddy Guddati <santhosh.reddy.guddati at intel.com>
---
 lib/igt_kms.c | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/lib/igt_kms.c b/lib/igt_kms.c
index 3d061abc5..21a6a4639 100644
--- a/lib/igt_kms.c
+++ b/lib/igt_kms.c
@@ -6394,6 +6394,11 @@ bool bigjoiner_mode_found(int drm_fd, drmModeConnector *connector,
 			  int max_dotclock, drmModeModeInfo *mode)
 {
 	bool found = false;
+	drmModeModeInfo *modes_backup;
+
+	modes_backup = malloc(connector->count_modes * sizeof(drmModeModeInfo));
+	igt_assert(modes_backup);
+	memcpy(modes_backup, connector->modes, connector->count_modes * sizeof(drmModeModeInfo));
 
 	igt_sort_connector_modes(connector, sort_drm_modes_by_res_dsc);
 	found = igt_bigjoiner_possible(drm_fd, &connector->modes[0], max_dotclock);
@@ -6401,8 +6406,14 @@ bool bigjoiner_mode_found(int drm_fd, drmModeConnector *connector,
 		igt_sort_connector_modes(connector, sort_drm_modes_by_clk_dsc);
 		found = igt_bigjoiner_possible(drm_fd, &connector->modes[0], max_dotclock);
 	}
-	if (found)
+	if (found) {
 		*mode = connector->modes[0];
+	} else {
+		memcpy(connector->modes, modes_backup,
+		       connector->count_modes * sizeof(drmModeModeInfo));
+	}
+
+	free(modes_backup);
 	return found;
 }
 
@@ -6438,6 +6449,11 @@ bool ultrajoiner_mode_found(int drm_fd, drmModeConnector *connector,
 			  int max_dotclock, drmModeModeInfo *mode)
 {
 	bool found = false;
+	drmModeModeInfo *modes_backup;
+
+	modes_backup = malloc(connector->count_modes * sizeof(drmModeModeInfo));
+	igt_assert(modes_backup);
+	memcpy(modes_backup, connector->modes, connector->count_modes * sizeof(drmModeModeInfo));
 
 	igt_sort_connector_modes(connector, sort_drm_modes_by_res_dsc);
 	found = igt_ultrajoiner_possible(&connector->modes[0], max_dotclock);
@@ -6445,8 +6461,14 @@ bool ultrajoiner_mode_found(int drm_fd, drmModeConnector *connector,
 		igt_sort_connector_modes(connector, sort_drm_modes_by_clk_dsc);
 		found = igt_ultrajoiner_possible(&connector->modes[0], max_dotclock);
 	}
-	if (found)
+	if (found) {
 		*mode = connector->modes[0];
+	} else {
+		memcpy(connector->modes, modes_backup,
+		       connector->count_modes * sizeof(drmModeModeInfo));
+	}
+
+	free(modes_backup);
 	return found;
 }
 
-- 
2.43.0