From d57a25815398ae83eae8bdcb3a1b607760aa30b6 Mon Sep 17 00:00:00 2001
From: Keith Packard <keithp@guitar.keithp.com>
Date: Tue, 12 Dec 2006 22:48:21 -0800
Subject: [PATCH] Elide duplicate modes in pScrn->monitor.

xf86DDCMonitorSet dumps all of the DDC-discovered modes
into the monitor mode list without checking to see if they
are already present. This provides an ever-changing list of
modes for outputs which have no DDC and which simply duplicate the monitor
mode list.
---
 src/i830_xf86Crtc.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/src/i830_xf86Crtc.c b/src/i830_xf86Crtc.c
index a222382d..6f96d448 100644
--- a/src/i830_xf86Crtc.c
+++ b/src/i830_xf86Crtc.c
@@ -337,6 +337,30 @@ xf86DefaultScreenLimits (ScrnInfoPtr pScrn, int *widthp, int *heightp)
     *heightp = height;
 }
 
+/*
+ * XXX walk the monitor mode list and prune out duplicates that
+ * are inserted by xf86DDCMonitorSet. In an ideal world, that
+ * function would do this work by itself.
+ */
+
+static void
+xf86PruneDuplicateMonitorModes (MonPtr Monitor)
+{
+    DisplayModePtr  master, clone, next;
+
+    for (master = Monitor->Modes; 
+	 master && master != Monitor->Last; 
+	 master = master->next)
+    {
+	for (clone = master->next; clone && clone != Monitor->Modes; clone = next)
+	{
+	    next = clone->next;
+	    if (xf86ModesEqual (master, clone))
+		xf86DeleteMode (&Monitor->Modes, clone);
+	}
+    }
+}
+
 void
 xf86ProbeOutputModes (ScrnInfoPtr pScrn)
 {
@@ -344,6 +368,9 @@ xf86ProbeOutputModes (ScrnInfoPtr pScrn)
     Bool		properties_set = FALSE;
     int			o;
 
+    /* Elide duplicate modes before defaulting code uses them */
+    xf86PruneDuplicateMonitorModes (pScrn->monitor);
+    
     /* Probe the list of modes for each output. */
     for (o = 0; o < config->num_output; o++) 
     {