[PATCH i-g-t 1/2] lib/igt_kms: Add helper to validate modes

[Karthik B S <karthik.b.s@intel.com>]

Add a helper function kmstest_mode_is_valid() that checks if
a given drmModeModeInfo pointer is non-NULL and has positive
width, height, and pixel clock.

This allows tests to safely check if an output mode is usable before
assigning it to a pipe or creating a framebuffer.

Signed-off-by: Karthik B S <karthik.b.s@intel.com>
---
 lib/igt_kms.c | 14 ++++++++++++++
 lib/igt_kms.h |  1 +
 2 files changed, 15 insertions(+)

diff --git a/lib/igt_kms.c b/lib/igt_kms.c
index a58f41b48..9e5820d43 100644
--- a/lib/igt_kms.c
+++ b/lib/igt_kms.c
@@ -5197,6 +5197,20 @@ const char *igt_output_name(igt_output_t *output)
 	return output->name;
 }
 
+/**
+ * kmstest_mode_is_valid:
+ * @mode: pointer to drmModeModeInfo
+ *
+ * Returns: True if the mode is non-NULL and has valid width, height and RR.
+ */
+bool kmstest_mode_is_valid(const drmModeModeInfo *mode)
+{
+	return mode &&
+	       mode->hdisplay > 0 &&
+	       mode->vdisplay > 0 &&
+	       mode->vrefresh > 0;
+}
+
 /**
  * igt_output_get_mode:
  * @output: Target output
diff --git a/lib/igt_kms.h b/lib/igt_kms.h
index 4a814f0e9..e10441017 100644
--- a/lib/igt_kms.h
+++ b/lib/igt_kms.h
@@ -585,6 +585,7 @@ static inline igt_crtc_t *igt_crtc_for_pipe(igt_display_t *display, enum pipe pi
 }
 
 const char *igt_output_name(igt_output_t *output);
+bool kmstest_mode_is_valid(const drmModeModeInfo *mode);
 drmModeModeInfo *igt_output_get_mode(igt_output_t *output);
 drmModeModeInfo *igt_output_get_highres_mode(igt_output_t *output);
 drmModeModeInfo *igt_output_get_lowres_mode(igt_output_t *output);
-- 
2.43.0