1 files changed, 88 insertions, 41 deletions

diff --git a/src/mesa/drivers/dri/common/vblank.c b/src/mesa/drivers/dri/common/vblank.c
index eebe42d96a1..e7ed545f13c 100644
--- a/src/mesa/drivers/dri/common/vblank.c
+++ b/src/mesa/drivers/dri/common/vblank.c
@@ -210,20 +210,6 @@ GLuint driGetDefaultVBlankFlags( const driOptionCache *optionCache )
 
 /****************************************************************************/
 /**
- * Sets the default swap interval when the drawable is first bound to a
- * direct rendering context.
- */
-
-void driDrawableInitVBlank( __DRIdrawablePrivate *priv, GLuint flags )
-{
-   if ( priv->pdraw->swap_interval == (unsigned)-1 ) {
-      priv->pdraw->swap_interval = (flags & VBLANK_FLAG_THROTTLE) != 0 ? 1 : 0;
-   }
-}
-
-
-/****************************************************************************/
-/**
  * Wrapper to call \c drmWaitVBlank.  The main purpose of this function is to
  * wrap the error message logging.  The error message should only be logged
  * the first time the \c drmWaitVBlank fails.  If \c drmWaitVBlank is
@@ -262,6 +248,71 @@ static int do_wait( drmVBlank * vbl, GLuint * vbl_seq, int fd )
 
 /****************************************************************************/
 /**
+ * Sets the default swap interval when the drawable is first bound to a
+ * direct rendering context.
+ */
+
+void driDrawableInitVBlank( __DRIdrawablePrivate *priv, GLuint flags,
+			    GLuint *vbl_seq )
+{
+   if ( priv->pdraw->swap_interval == (unsigned)-1 ) {
+      /* Get current vertical blank sequence */
+      drmVBlank vbl = { .request={ .type = DRM_VBLANK_RELATIVE, .sequence = 0 } };
+      do_wait( &vbl, vbl_seq, priv->driScreenPriv->fd );
+
+      priv->pdraw->swap_interval = (flags & (VBLANK_FLAG_THROTTLE |
+					     VBLANK_FLAG_SYNC)) != 0 ? 1 : 0;
+   }
+}
+
+
+/****************************************************************************/
+/**
+ * Returns the current swap interval of the given drawable.
+ */
+
+unsigned
+driGetVBlankInterval( const  __DRIdrawablePrivate *priv, GLuint flags )
+{
+   if ( (flags & VBLANK_FLAG_INTERVAL) != 0 ) {
+      /* this must have been initialized when the drawable was first bound
+       * to a direct rendering context. */
+      assert ( priv->pdraw->swap_interval != (unsigned)-1 );
+
+      return priv->pdraw->swap_interval;
+   }
+   else if ( (flags & (VBLANK_FLAG_THROTTLE | VBLANK_FLAG_SYNC)) != 0 ) {
+      return 1;
+   }
+   else {
+      return 0;
+   }
+}
+
+
+/****************************************************************************/
+/**
+ * Returns the current vertical blank sequence number of the given drawable.
+ */
+
+void
+driGetCurrentVBlank( const  __DRIdrawablePrivate *priv, GLuint flags,
+		     GLuint *vbl_seq )
+{
+   drmVBlank vbl;
+
+   vbl.request.type = DRM_VBLANK_RELATIVE;
+   if ( flags & VBLANK_FLAG_SECONDARY ) {
+      vbl.request.type |= DRM_VBLANK_SECONDARY;
+   }
+   vbl.request.sequence = 0;
+
+   (void) do_wait( &vbl, vbl_seq, priv->driScreenPriv->fd );
+}
+
+
+/****************************************************************************/
+/**
  * Waits for the vertical blank for use with glXSwapBuffers.
  * 
  * \param vbl_seq  Vertical blank sequence number (MSC) after the last buffer
@@ -282,7 +333,7 @@ driWaitForVBlank( const  __DRIdrawablePrivate *priv, GLuint * vbl_seq,
    unsigned   original_seq;
    unsigned   deadline;
    unsigned   interval;
-
+   unsigned   diff;
 
    *missed_deadline = GL_FALSE;
    if ( (flags & (VBLANK_FLAG_INTERVAL |
@@ -304,44 +355,40 @@ driWaitForVBlank( const  __DRIdrawablePrivate *priv, GLuint * vbl_seq,
     */
 
    original_seq = *vbl_seq;
+   interval = driGetVBlankInterval(priv, flags);
+   deadline = original_seq + interval;
 
-   vbl.request.sequence = ((flags & VBLANK_FLAG_SYNC) != 0) ? 1 : 0;
    vbl.request.type = DRM_VBLANK_RELATIVE;
-      
+   if ( flags & VBLANK_FLAG_SECONDARY ) {
+      vbl.request.type |= DRM_VBLANK_SECONDARY;
+   }
+   vbl.request.sequence = ((flags & VBLANK_FLAG_SYNC) != 0) ? 1 : 0;
+
    if ( do_wait( & vbl, vbl_seq, priv->driScreenPriv->fd ) != 0 ) {
       return -1;
    }
 
-	
-   vbl.request.type = DRM_VBLANK_ABSOLUTE;
+   diff = *vbl_seq - deadline;
 
-   if ( (flags & VBLANK_FLAG_INTERVAL) != 0 ) {
-      interval = priv->pdraw->swap_interval;
-      /* this must have been initialized when the drawable was first bound
-       * to a direct rendering context. */
-      assert ( interval != (unsigned)-1 );
-   }
-   else if ( (flags & VBLANK_FLAG_THROTTLE) != 0 ) {
-      interval = 1;
-   }
-   else {
-      interval = 0;
+   /* No need to wait again if we've already reached the target */
+   if (diff <= (1 << 23)) {
+      *missed_deadline = (flags & VBLANK_FLAG_SYNC) ? (diff > 0) : GL_TRUE;
+      return 0;
    }
 
+   /* Wait until the target vertical blank. */
+   vbl.request.type = DRM_VBLANK_ABSOLUTE;
+   if ( flags & VBLANK_FLAG_SECONDARY ) {
+      vbl.request.type |= DRM_VBLANK_SECONDARY;
+   }
+   vbl.request.sequence = deadline;
 
-   /* Wait until the next vertical blank.  If the interval is zero, then
-    * the deadline is one vertical blank after the previous wait.
-    */
-
-   vbl.request.sequence = original_seq + interval;
-   if ( *vbl_seq < vbl.request.sequence ) {
-      if ( do_wait( & vbl, vbl_seq, priv->driScreenPriv->fd ) != 0 ) {
-	 return -1;
-      }
+   if ( do_wait( & vbl, vbl_seq, priv->driScreenPriv->fd ) != 0 ) {
+      return -1;
    }
 
-   deadline = original_seq + ((interval == 0) ? 1 : interval);
-   *missed_deadline = ( *vbl_seq > deadline );
+   diff = *vbl_seq - deadline;
+   *missed_deadline = diff > 0 && diff <= (1 << 23);
 
    return 0;
 }