drm: introduce generation counter to interface.

Idea being if you want to add new crtc/output/encoder dynamically later,
you just increase the generation counter and userspace should re-read
all the resources

1 files changed, 10 insertions, 1 deletions

diff --git a/libdrm/xf86drmMode.h b/libdrm/xf86drmMode.h
index 56908d8f..3bd30a92 100644
--- a/libdrm/xf86drmMode.h
+++ b/libdrm/xf86drmMode.h
@@ -51,9 +51,16 @@
  * buffer object interface. This object needs to be pinned.
  */
 
+/*
+ * generation - these are to be read by userspace, and if it notices
+ * while calling a get output or get crtc that the generation has changed
+ * it should re-call the mode resource functions resync its view of the
+ * outputs with current view.
+ */
 
 typedef struct _drmModeRes {
 
+	uint32_t generation;
 	int count_fbs;
 	uint32_t *fbs;
 
@@ -93,6 +100,7 @@ typedef struct _drmModeProperty {
 typedef struct _drmModeCrtc {
 	unsigned int crtc_id;
 	unsigned int buffer_id; /**< FB id to connect to 0 = disconnect*/
+	uint32_t generation;
 
 	uint32_t x, y; /**< Position on the frameuffer */
 	uint32_t width, height;
@@ -110,6 +118,7 @@ typedef struct _drmModeCrtc {
 } drmModeCrtc, *drmModeCrtcPtr;
 
 typedef struct _drmModeEncoder {
+	uint32_t generation;
 	unsigned int encoder_id;
 	unsigned int encoder_type;
 	uint32_t crtc;
@@ -133,8 +142,8 @@ typedef enum {
 } drmModeSubPixel;
 
 typedef struct _drmModeConnector {
+	uint32_t generation;
 	unsigned int connector_id;
-
 	unsigned int encoder; /**< Crtc currently connected to */
 	unsigned int connector_type;
 	unsigned int connector_type_id;