[PATCH i-g-t 08/14] lib/igt_kms: add helper to get pending lt failures

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

i915_dp_force_link_training_failure can be written to
written to trigger link trainig failures on retrain.
add helper to get pending link training failure count.

Signed-off-by: Kunal Joshi <kunal1.joshi@intel.com>
---
 lib/igt_kms.c | 23 +++++++++++++++++++++++
 lib/igt_kms.h |  1 +
 2 files changed, 24 insertions(+)

diff --git a/lib/igt_kms.c b/lib/igt_kms.c
index 4ab47e2e9..727fa83f1 100644
--- a/lib/igt_kms.c
+++ b/lib/igt_kms.c
@@ -6918,3 +6918,26 @@ bool igt_has_force_link_training_failure_debugfs(int drmfd, igt_output_t *output
 	close(debugfs_fd);
 	return ret >= 0;
 }
+
+/**
+ * igt_get_dp_pending_lt_failures:
+ * @drm_fd: A drm file descriptor
+ * @output: Target output
+ *
+ * Returns: Number of pending link training failures.
+ */
+int igt_get_dp_pending_lt_failures(int drm_fd, igt_output_t *output)
+{
+	int dir, res, ret;
+	char buf[512];
+
+	igt_require_f(output->name, "Invalid output");
+	dir = igt_debugfs_connector_dir(drm_fd, output->name, O_RDONLY);
+	igt_assert_f(dir >= 0, "Failed to open debugfs dir for connector %s\n",
+			       igt_output_name(output));
+	res = igt_debugfs_simple_read(dir, "i915_dp_force_link_training_failure", buf, sizeof(buf));
+	close(dir);
+	igt_require(res > 0);
+	sscanf(buf, "%d", &ret);
+	return ret;
+}
diff --git a/lib/igt_kms.h b/lib/igt_kms.h
index 5ae324f6f..07dbcb263 100644
--- a/lib/igt_kms.h
+++ b/lib/igt_kms.h
@@ -1255,5 +1255,6 @@ void igt_force_link_retrain(int drm_fd, igt_output_t *output, int retrain_count)
 void igt_force_lt_failure(int drm_fd, igt_output_t *output, int failure_count);
 bool igt_get_dp_link_retrain_disabled(int drm_fd, igt_output_t *output);
 bool igt_has_force_link_training_failure_debugfs(int drmfd, igt_output_t *output);
+int igt_get_dp_pending_lt_failures(int drm_fd, igt_output_t *output);
 
 #endif /* __IGT_KMS_H__ */
-- 
2.34.1