tests/kms_force_connector_basic: Add prune-stale-modes subtest

Add a new subtest that makes sure old stale modes get pruned from the
connector's mode list when the EDID changes.

v2: s/drmModeGetConnector/drmModeGetConnectorCurrent/ since
    kmstest_force_edid() already takes care of doing the heavier
    call for us (Daniel)

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>

lib/igt_kms.c

@@ -111,6 +111,46 @@ const unsigned char* igt_kms_get_base_edid(void)
 	return base_edid;
 }
 
+#define VFREQ 60
+#define CLOCK 101000
+#define HACTIVE 1400
+#define HBLANK 160
+#define VACTIVE 1050
+#define VBLANK 30
+#define HOFFSET 48
+#define HPULSE 32
+#define VOFFSET 3
+#define VPULSE 4
+
+#define HSIZE 52
+#define VSIZE 30
+
+#define EDID_NAME alt_edid
+#include "igt_edid_template.h"
+
+/**
+ * igt_kms_get_alt_edid:
+ *
+ * Get an alternate edid block, which includes the following modes:
+ *
+ *  - 1400x1050 60Hz
+ *  - 1920x1080 60Hz
+ *  - 1280x720 60Hz
+ *  - 1024x768 60Hz
+ *  - 800x600 60Hz
+ *  - 640x480 60Hz
+ *
+ * This can be extended with further features using functions such as
+ * #kmstest_edid_add_3d.
+ *
+ * Returns: an alternate edid block
+ */
+const unsigned char* igt_kms_get_alt_edid(void)
+{
+	update_edid_csum(alt_edid);
+
+	return alt_edid;
+}
 
 /**
  * SECTION:igt_kms

lib/igt_kms.h

@@ -286,6 +286,7 @@ void igt_reset_connectors(void);
 
 #define EDID_LENGTH 128
 const unsigned char* igt_kms_get_base_edid(void);
+const unsigned char* igt_kms_get_alt_edid(void);
 
 
 #endif /* __IGT_KMS_H__ */