ecore_drm2: Add a page flip completion call

Add a function for ecore_evas_drm to call after a page flip happens so
ecore_drm2 can track busy status for fbs itself (including for the fb
that's currently being flipped to scanout)

Also, call the completion function from ecore_evas_drm

src/lib/ecore_drm2/Ecore_Drm2.h

@@ -768,6 +768,9 @@ EAPI void ecore_drm2_fb_dirty(Ecore_Drm2_Fb *fb, Eina_Rectangle *rects, unsigned
 /**
  * Schedule a pageflip to the given Ecore_Drm2_Fb
  *
+ * The caller is responsible for running a page flip handler
+ * and calling ecore_drm2_fb_flip_complete() when it completes.
+ *
  * @param fb
  * @param output
  *
@@ -778,6 +781,18 @@ EAPI void ecore_drm2_fb_dirty(Ecore_Drm2_Fb *fb, Eina_Rectangle *rects, unsigned
  */
 EAPI int ecore_drm2_fb_flip(Ecore_Drm2_Fb *fb, Ecore_Drm2_Output *output);
 
+/**
+ * Must be called by a page flip handler when the flip completes.
+ *
+ * @param output
+ *
+ * @return Whether there's an undisplayed buffer still in the queue.
+ *
+ * @ingroup Ecore_Drm2_Fb_Group
+ * @since 1.18
+ */
+EAPI Eina_Bool ecore_drm2_fb_flip_complete(Ecore_Drm2_Output *output);
+
 /**
  * Return the Ecore_Drm2_Fb's busy status
  *

src/lib/ecore_drm2/ecore_drm2_fb.c

@@ -223,6 +223,19 @@ ecore_drm2_fb_dirty(Ecore_Drm2_Fb *fb, Eina_Rectangle *rects, unsigned int count
 #endif
 }
 
+EAPI Eina_Bool
+ecore_drm2_fb_flip_complete(Ecore_Drm2_Output *output)
+{
+   if (output->current) output->current->busy = EINA_FALSE;
+   output->current = output->pending;
+   output->pending = NULL;
+
+   /* In case they were the same buffer... */
+   if (output->current) output->current->busy = EINA_TRUE;
+
+   return !!output->next;
+}
+
 EAPI int
 ecore_drm2_fb_flip(Ecore_Drm2_Fb *fb, Ecore_Drm2_Output *output)
 {
@@ -233,6 +246,13 @@ ecore_drm2_fb_flip(Ecore_Drm2_Fb *fb, Ecore_Drm2_Output *output)
 
    if (!output->enabled) return -1;
 
+   if (output->pending)
+     {
+        if (output->next) output->next->busy = EINA_FALSE;
+        output->next = fb;
+        if (output->next) output->next->busy = EINA_TRUE;
+        return 0;
+     }
    if (!fb) fb = output->next;
 
    /* So we can generate a tick by flipping to the current fb */
@@ -262,7 +282,9 @@ ecore_drm2_fb_flip(Ecore_Drm2_Fb *fb, Ecore_Drm2_Output *output)
              return ret;
           }
 
+        if (output->current) output->current->busy = EINA_FALSE;
         output->current = fb;
+        output->current->busy = EINA_TRUE;
         output->next = NULL;
 
         return 0;
@@ -284,9 +306,8 @@ ecore_drm2_fb_flip(Ecore_Drm2_Fb *fb, Ecore_Drm2_Output *output)
         return 0;
      }
 
-   if (output->current) output->current->busy = EINA_FALSE;
-   output->current = fb;
-   fb->busy = EINA_TRUE;
+   output->pending = fb;
+   output->pending->busy = EINA_TRUE;
    return 0;
 }
 

src/lib/ecore_drm2/ecore_drm2_private.h

@@ -138,7 +138,7 @@ struct _Ecore_Drm2_Output
 
    drmModeCrtcPtr ocrtc;
 
-   Ecore_Drm2_Fb *current, *next;
+   Ecore_Drm2_Fb *current, *next, *pending;
 
    Eina_Matrix4 matrix, inverse;
    Ecore_Drm2_Transform transform;

src/modules/ecore_evas/engines/drm/ecore_evas_drm.c

@@ -639,6 +639,8 @@ _cb_pageflip(int fd EINA_UNUSED, unsigned int frame EINA_UNUSED, unsigned int se
    ee = data;
    edata = ee->engine.data;
 
+   ecore_drm2_fb_flip_complete(edata->output);
+
    next = ecore_drm2_output_next_fb_get(edata->output);
    if (next)
      {