[igt-dev] [PATCH i-g-t v2] tests/kms_display_modes: Fixed mode selection for extended mode tests

[Mohammed Thasleem <mohammed.thasleem@intel.com>]

Added check on ENOSPC when two moniters connected through MST.
This will find the connector mode combo that fits into the
bandwidth when more than one monitor is connected.

Example:
  When two monitors connected through MST, the second monitor
  also tries to use the same mode. So two such modes may not
  fit into the link bandwidth. So, iterate through connected
  outputs & modes and find a combination of modes those fit
  into the link BW.

v2: -Updated commit msg and description. (Bhanu)
    -Renamed restart with retry. (Bhanu)
    -Moved igt_pipe_crc_new before retry. (Bhanu)
    -Removed unrelated changes and new line. (Bhanu)
    -Minor changes.

Signed-off-by: Mohammed Thasleem <mohammed.thasleem@intel.com>
---
 tests/kms_display_modes.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/tests/kms_display_modes.c b/tests/kms_display_modes.c
index e4191811..19026dc1 100644
--- a/tests/kms_display_modes.c
+++ b/tests/kms_display_modes.c
@@ -43,7 +43,7 @@ static void run_extendedmode_basic(data_t *data, int pipe1, int pipe2)
 	igt_plane_t *plane[2];
 	igt_pipe_crc_t *pipe_crc[2] = { 0 };
 	igt_crc_t ref_crc[2], crc[2];
-	int count = 0, width, height;
+	int count = 0, width, height, ret;
 	cairo_t *cr;
 
 	for_each_connected_output(display, output) {
@@ -54,14 +54,16 @@ static void run_extendedmode_basic(data_t *data, int pipe1, int pipe2)
 			break;
 	}
 
+	pipe_crc[0] = igt_pipe_crc_new(data->drm_fd, pipe1, IGT_PIPE_CRC_SOURCE_AUTO);
+	pipe_crc[1] = igt_pipe_crc_new(data->drm_fd, pipe2, IGT_PIPE_CRC_SOURCE_AUTO);
+
+retry:
 	igt_output_set_pipe(extended_output[0], pipe1);
 	igt_output_set_pipe(extended_output[1], pipe2);
 
 	mode[0] = igt_output_get_mode(extended_output[0]);
 	mode[1] = igt_output_get_mode(extended_output[1]);
 
-	pipe_crc[0] = igt_pipe_crc_new(data->drm_fd, pipe1, IGT_PIPE_CRC_SOURCE_AUTO);
-	pipe_crc[1] = igt_pipe_crc_new(data->drm_fd, pipe2, IGT_PIPE_CRC_SOURCE_AUTO);
 
 	igt_create_color_fb(data->drm_fd, mode[0]->hdisplay, mode[0]->vdisplay,
 			     DRM_FORMAT_XRGB8888, 0, 1, 0, 0, &fbs[0]);
@@ -79,7 +81,22 @@ static void run_extendedmode_basic(data_t *data, int pipe1, int pipe2)
 	igt_fb_set_size(&fbs[1], plane[1], mode[1]->hdisplay, mode[1]->vdisplay);
 	igt_plane_set_size(plane[1], mode[1]->hdisplay, mode[1]->vdisplay);
 
-	igt_display_commit2(display, COMMIT_ATOMIC);
+	ret = igt_display_try_commit2(display, COMMIT_ATOMIC);
+	if (ret != 0 && errno == ENOSPC) {
+		bool found = igt_override_all_active_output_modes_to_fit_bw(display);
+
+		igt_require_f(found, "No valid mode combo found.\n");
+
+		for_each_connected_output(display, output)
+			igt_output_set_pipe(output, PIPE_NONE);
+
+		igt_remove_fb(data->drm_fd, &fbs[0]);
+		igt_remove_fb(data->drm_fd, &fbs[1]);
+
+		goto retry;
+	}
+
+	igt_assert(!ret);
 
 	igt_pipe_crc_collect_crc(pipe_crc[0], &ref_crc[0]);
 	igt_pipe_crc_collect_crc(pipe_crc[1], &ref_crc[1]);
-- 
2.25.1