[PATCH] crtc: match full preferred modes if possible when choosing an initial config

[Jesse Barnes]

It's fairly common to have multiple, identical monitors plugged in.  In
that case, it's preferable to run the monitor's preferred mode on each
output, rather than just matching the width & height and end up with
different timings or refresh rates.

Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
---
 hw/xfree86/modes/xf86Crtc.c |   25 ++++++++++++++++++++-----
 1 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/hw/xfree86/modes/xf86Crtc.c b/hw/xfree86/modes/xf86Crtc.c
index 3fae039..d75cd77 100644
--- a/hw/xfree86/modes/xf86Crtc.c
+++ b/hw/xfree86/modes/xf86Crtc.c
@@ -2060,13 +2060,28 @@ xf86TargetPreferred(ScrnInfoPtr scrn, xf86CrtcConfigPtr config,
 		if (o == p)
 		    continue;
 
-		for (mode = output->probed_modes; mode; mode = mode->next) {
-		    Rotation r = output->initial_rotation;
-		    if (xf86ModeWidth(mode, r) == pref_width &&
-			    xf86ModeHeight(mode, r) == pref_height) {
+		/*
+		 * First see if the preferred mode matches on the next
+		 * output as well.  This catches the common case of identical
+		 * monitors and makes sure they all have the same timings
+		 * and refresh.  If that fails, we fall back to trying to
+		 * match just width & height.
+		 */
+		mode = xf86OutputHasPreferredMode(output, pref_width,
+						  pref_height);
+		if (mode && xf86ModesEqual(mode, preferred[p])) {
 			preferred[o] = mode;
 			match = TRUE;
-		    }
+		} else {
+			for (mode = output->probed_modes; mode;
+			     mode = mode->next) {
+				Rotation r = output->initial_rotation;
+				if (xf86ModeWidth(mode, r) == pref_width &&
+				    xf86ModeHeight(mode, r) == pref_height) {
+					preferred[o] = mode;
+					match = TRUE;
+				}
+			}
 		}
 
 		all_match &= match;
-- 
1.7.4.1