[PATCH i-g-t 2/2] tests/intel/kms_joiner: Use the CRTCs reported free before a modeset

[Arun R Murthy <arun.r.murthy@intel.com>]

Every joiner modeset here picks pipes out of BIT(n_pipes) - 1, i.e. it
assumes all pipes are free, and the ultra joiner and last-pipe paths
pick a pipe without checking it at all. When another client owns a
pipe the commit fails for an unrelated reason and the subtest reports
a bogus failure.

Query the free pipes with igt_get_free_pipes_mask() right before each
modeset sequence and use only those CRTCs that are available.
igt_display_reset doesnt land to KMD without committing, so
the pipes were never actually released before sampling; add the
missing commit.

Assisted-by: LLM
Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
---
 tests/intel/kms_joiner.c | 75 ++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 70 insertions(+), 5 deletions(-)

diff --git a/tests/intel/kms_joiner.c b/tests/intel/kms_joiner.c
index fce24f2bd08767351c1b323cc0a7f03c6d2fa0ec..c0e358a319734b8876deffe74e0416474b7e64e5 100644
--- a/tests/intel/kms_joiner.c
+++ b/tests/intel/kms_joiner.c
@@ -131,6 +131,21 @@ static void enable_force_joiner_on_all_non_ultra_joiner_outputs(data_t *data)
 	}
 }
 
+/*
+ * A joiner modeset needs @count consecutive free pipes starting at @pipe.
+ * @free_pipe_mask is the snapshot taken from drmModeGetCrtcList().
+ */
+static bool pipes_are_free(uint32_t free_pipe_mask, enum hardware_pipe pipe, int count)
+{
+	uint32_t needed_mask = 0;
+	int i;
+
+	for (i = 0; i < count; i++)
+		needed_mask |= BIT(pipe + i);
+
+	return (free_pipe_mask & needed_mask) == needed_mask;
+}
+
 static enum hardware_pipe get_next_master_pipe(data_t *data, uint32_t available_pipe_mask)
 {
 	if ((data->master_pipes & available_pipe_mask) == 0)
@@ -223,7 +238,8 @@ static void switch_modeset_ultra_joiner_big_joiner(data_t *data, igt_output_t *o
 	drmModeModeInfo uj_mode;
 	int status;
 	bool ultrajoiner_found;
-	enum hardware_pipe pipe;
+	/* set_joiner_mode() always drives pipe A */
+	enum hardware_pipe pipe = PIPE_A;
 	bool force_joiner_supported;
 
 	drmModeConnector *connector = output->config.connector;
@@ -246,6 +262,14 @@ static void switch_modeset_ultra_joiner_big_joiner(data_t *data, igt_output_t *o
 	}
 
 	igt_dynamic_f("pipe-%s-%s", kmstest_pipe_name(pipe), output->name) {
+		/* Release the pipes a previous output was using if any */
+		igt_display_reset(&data->display);
+		igt_display_commit2(&data->display, COMMIT_ATOMIC);
+		igt_require_f(pipes_are_free(igt_get_free_pipes_mask(&data->display),
+					     pipe, 4),
+			      "No 4 free consecutive pipes starting at %s\n",
+			      kmstest_pipe_name(pipe));
+
 		set_joiner_mode(data, output, &uj_mode);
 		/* Switch to big joiner mode */
 		if (bigjoiner_mode_found(data->drm_fd, output->config.connector,
@@ -279,7 +303,7 @@ static void test_single_joiner(data_t *data, int output_count, bool force_joiner
 {
 	int i;
 	enum hardware_pipe pipe, master_pipe;
-	uint32_t available_pipe_mask = BIT(data->n_pipes) - 1;
+	uint32_t available_pipe_mask;
 	igt_output_t *output;
 	igt_plane_t *primary;
 	igt_output_t **outputs;
@@ -290,6 +314,9 @@ static void test_single_joiner(data_t *data, int output_count, bool force_joiner
 	igt_display_reset(&data->display);
 	igt_display_commit2(&data->display, COMMIT_ATOMIC);
 
+	available_pipe_mask = igt_get_free_pipes_mask(&data->display);
+	igt_require_f(available_pipe_mask, "No free CRTC available\n");
+
 	for (i = 0; i < output_count; i++) {
 		output = outputs[i];
 		for (pipe = 0; pipe < data->n_pipes - 1; pipe++) {
@@ -320,13 +347,15 @@ static void test_multi_joiner(data_t *data, int output_count, bool force_joiner)
 	igt_fb_t fb[output_count];
 	drmModeModeInfo *mode;
 
-	available_pipe_mask = BIT(data->n_pipes) - 1;
 	outputs = force_joiner ? data->non_big_joiner_output : data->big_joiner_output;
 	cleanup = 0;
 
 	igt_display_reset(&data->display);
 	igt_display_commit2(&data->display, COMMIT_ATOMIC);
 
+	available_pipe_mask = igt_get_free_pipes_mask(&data->display);
+	igt_require_f(available_pipe_mask, "No free CRTC available\n");
+
 	for (i = 0; i < output_count; i++) {
 		output = outputs[i];
 		for (pipe = 0; pipe < data->n_pipes; pipe++) {
@@ -366,12 +395,14 @@ static void test_invalid_modeset_two_joiner(data_t *data,
 	igt_fb_t fb[INVALID_TEST_OUTPUT];
 	drmModeModeInfo mode;
 
-	available_pipe_mask = BIT(data->n_pipes) - 1;
 	outputs = force_joiner ? data->non_big_joiner_output :
 		  mixed ? data->mixed_output : data->big_joiner_output;
 	igt_display_reset(&data->display);
 	igt_display_commit2(&data->display, COMMIT_ATOMIC);
 
+	available_pipe_mask = igt_get_free_pipes_mask(&data->display);
+	igt_require_f(available_pipe_mask, "No free CRTC available\n");
+
 	for (i = 0; i < data->n_pipes - 1; i++) {
 		attempt_mask = BIT(data->pipe_seq[i]);
 		master_pipe = get_next_master_pipe(data, available_pipe_mask & attempt_mask);
@@ -447,6 +478,12 @@ static void test_joiner_on_last_pipe(data_t *data, bool force_joiner)
 		igt_display_commit2(&data->display, COMMIT_ATOMIC);
 		output = outputs[i];
 
+		if (!pipes_are_free(igt_get_free_pipes_mask(display), pipe, 1)) {
+			igt_info("Pipe %s is not free, skipping output %s\n",
+				 kmstest_pipe_name(pipe), output->name);
+			continue;
+		}
+
 		if (!force_joiner) {
 			igt_require_f(bigjoiner_mode_found(data->drm_fd, output->config.connector, max_dotclock, &mode),
 						  "No big joiner mode found on output %s\n", output->name);
@@ -478,7 +515,8 @@ static void test_joiner_on_last_pipe(data_t *data, bool force_joiner)
 static void test_ultra_joiner(data_t *data, bool invalid_pipe, bool two_display, bool force_joiner)
 {
 	igt_display_t *display = &data->display;
-	int i, j, k, ret, count;
+	int i, j, k, ret, count, needed_pipes;
+	uint32_t free_pipe_mask;
 	igt_output_t *output, *non_ultra_joiner_output;
 	igt_plane_t *primary;
 	igt_output_t **outputs;
@@ -496,6 +534,16 @@ static void test_ultra_joiner(data_t *data, bool invalid_pipe, bool two_display,
 	igt_display_reset(&data->display);
 	igt_display_commit2(&data->display, COMMIT_ATOMIC);
 
+	/*
+	 * A successful ultra joiner modeset occupies four consecutive pipes,
+	 * so all four have to be free.
+	 * The invalid_pipe is a -ve test & expects the commit to be rejected,
+	 * so dont skip the test if 4 pipes are not available, allow it to fail.
+	 */
+	needed_pipes = invalid_pipe ? 1 : 4;
+	free_pipe_mask = igt_get_free_pipes_mask(&data->display);
+	igt_require_f(free_pipe_mask, "No free CRTC available\n");
+
 	for (i = 0; i < count; i++) {
 		output = outputs[i];
 
@@ -519,6 +567,14 @@ static void test_ultra_joiner(data_t *data, bool invalid_pipe, bool two_display,
 				continue;
 
 			pipe = data->pipe_seq[j];
+
+			if (!pipes_are_free(free_pipe_mask, pipe, needed_pipes)) {
+				igt_info("No %d free consecutive pipes from %s, skipping output %s\n",
+					 needed_pipes, kmstest_pipe_name(pipe),
+					 output->name);
+				continue;
+			}
+
 			crtc = igt_crtc_for_pipe(display, pipe);
 			igt_assert_f(crtc, "There is no pipe %s\n", kmstest_pipe_name(pipe));
 
@@ -579,6 +635,7 @@ static void test_basic_max_non_joiner(data_t *data)
 {
 	igt_display_t *display = &data->display;
 	int count;
+	uint32_t free_pipe_mask;
 	enum hardware_pipe pipe;
 	igt_output_t **outputs, *output;
 	igt_fb_t fb;
@@ -588,6 +645,10 @@ static void test_basic_max_non_joiner(data_t *data)
 	count = data->non_joiner_output_count;
 	outputs = data->non_joiner_output;
 	igt_display_reset(&data->display);
+	igt_display_commit2(&data->display, COMMIT_ATOMIC);
+
+	/* A non-joiner modeset needs a single free pipe. */
+	free_pipe_mask = igt_get_free_pipes_mask(&data->display);
 
 	for (int i = 0; i < count; i++) {
 		output = outputs[i];
@@ -596,6 +657,10 @@ static void test_basic_max_non_joiner(data_t *data)
 			igt_dynamic_f("pipe-%s-%s", kmstest_pipe_name(pipe), output->name) {
 				igt_crtc_t *crtc;
 
+				igt_require_f(pipes_are_free(free_pipe_mask, pipe, 1),
+					      "Pipe %s is not free\n",
+					      kmstest_pipe_name(pipe));
+
 				crtc = igt_crtc_for_pipe(display, pipe);
 				igt_assert_f(crtc, "There is no pipe %s\n", kmstest_pipe_name(pipe));
 

-- 
2.25.1