Add a canGrow argument to xf86InitialConfiguration.

canGrow indicates to the DDX that the driver can enlarge the desktop via the
xf86_config->funcs->resize hook.  If so, xf86InitialConfiguration will set
virtual[XY] to match the configuration it chooses and will leave the crtc config
size ranges alone.  If FALSE, it will bloat the screen to fit the largest probed
mode and also set the crtc config max size to limit the desktop to the initial
virtual[XY] size.

hw/xfree86/modes/xf86Crtc.c

@@ -734,12 +734,16 @@ xf86PickCrtcs (ScrnInfoPtr	scrn,
 
 /*
  * Compute the virtual size necessary to place all of the available
- * crtcs in the specified configuration and also large enough to
- * resize any crtc to the largest available mode
+ * crtcs in the specified configuration.
+ *
+ * canGrow indicates that the driver can make the screen larger than its initial
+ * configuration.  If FALSE, this function will enlarge the screen to include
+ * the largest available mode.
  */
 
 static void
-xf86DefaultScreenLimits (ScrnInfoPtr scrn, int *widthp, int *heightp)
+xf86DefaultScreenLimits (ScrnInfoPtr scrn, int *widthp, int *heightp,
+			 Bool canGrow)
 {
     xf86CrtcConfigPtr	config = XF86_CRTC_CONFIG_PTR(scrn);
     int	    width = 0, height = 0;
@@ -757,26 +761,28 @@ xf86DefaultScreenLimits (ScrnInfoPtr scrn, int *widthp, int *heightp)
 	    crtc_width = crtc->x + xf86ModeWidth (&crtc->desiredMode, crtc->desiredRotation);
 	    crtc_height = crtc->y + xf86ModeHeight (&crtc->desiredMode, crtc->desiredRotation);
 	}
-	for (o = 0; o < config->num_output; o++) 
-	{
-	    xf86OutputPtr   output = config->output[o];
+	if (!canGrow) {
+	    for (o = 0; o < config->num_output; o++)
+	    {
+		xf86OutputPtr   output = config->output[o];
 
-	    for (s = 0; s < config->num_crtc; s++)
-		if (output->possible_crtcs & (1 << s))
-		{
-		    DisplayModePtr  mode;
-		    for (mode = output->probed_modes; mode; mode = mode->next)
+		for (s = 0; s < config->num_crtc; s++)
+		    if (output->possible_crtcs & (1 << s))
 		    {
-			if (mode->HDisplay > crtc_width)
-			    crtc_width = mode->HDisplay;
-			if (mode->VDisplay > crtc_width)
-			    crtc_width = mode->VDisplay;
-			if (mode->VDisplay > crtc_height)
-			    crtc_height = mode->VDisplay;
-			if (mode->HDisplay > crtc_height)
-			    crtc_height = mode->HDisplay;
+			DisplayModePtr  mode;
+			for (mode = output->probed_modes; mode; mode = mode->next)
+			{
+			    if (mode->HDisplay > crtc_width)
+				crtc_width = mode->HDisplay;
+			    if (mode->VDisplay > crtc_width)
+				crtc_width = mode->VDisplay;
+			    if (mode->VDisplay > crtc_height)
+				crtc_height = mode->VDisplay;
+			    if (mode->HDisplay > crtc_height)
+				crtc_height = mode->HDisplay;
+			}
 		    }
-		}
+	    }
 	}
 	if (crtc_width > width)
 	    width = crtc_width;
@@ -1350,10 +1356,17 @@ xf86SetScrnInfoModes (ScrnInfoPtr scrn)
  *
  * Given auto-detected (and, eventually, configured) values,
  * construct a usable configuration for the system
+ *
+ * canGrow indicates that the driver can resize the screen to larger than its
+ * initially configured size via the config->funcs->resize hook.  If TRUE, this
+ * function will set virtualX and virtualY to match the initial configuration
+ * and leave config->max{Width,Height} alone.  If FALSE, it will bloat
+ * virtual[XY] to include the largest modes and set config->max{Width,Height}
+ * accordingly.
  */
 
 Bool
-xf86InitialConfiguration (ScrnInfoPtr	    scrn)
+xf86InitialConfiguration (ScrnInfoPtr scrn, Bool canGrow)
 {
     xf86CrtcConfigPtr	config = XF86_CRTC_CONFIG_PTR(scrn);
     int			o, c;
@@ -1491,9 +1504,10 @@ xf86InitialConfiguration (ScrnInfoPtr	    scrn)
     if (scrn->display->virtualX == 0)
     {
 	/*
-	 * Expand virtual size to cover potential mode switches
+	 * Expand virtual size to cover the current config and potential mode
+	 * switches, if the driver can't enlarge the screen later.
 	 */
-	xf86DefaultScreenLimits (scrn, &width, &height);
+	xf86DefaultScreenLimits (scrn, &width, &height, canGrow);
 
 	scrn->display->virtualX = width;
 	scrn->display->virtualY = height;
@@ -1503,7 +1517,23 @@ xf86InitialConfiguration (ScrnInfoPtr	    scrn)
 	scrn->virtualX = width;
     if (height > scrn->virtualY)
 	scrn->virtualY = height;
-
+
+    /*
+     * Make sure the configuration isn't too small.
+     */
+    if (width < config->minWidth || height < config->minHeight)
+	return FALSE;
+
+    /*
+     * Limit the crtc config to virtual[XY] if the driver can't grow the
+     * desktop.
+     */
+    if (!canGrow)
+    {
+	xf86CrtcSetSizeRange (scrn, config->minWidth, config->minHeight,
+			      width, height);
+    }
+
     /* Mirror output modes to scrn mode list */
     xf86SetScrnInfoModes (scrn);
 

hw/xfree86/modes/xf86Crtc.h

@@ -545,7 +545,7 @@ void
 xf86SetScrnInfoModes (ScrnInfoPtr pScrn);
 
 Bool
-xf86InitialConfiguration (ScrnInfoPtr pScrn);
+xf86InitialConfiguration (ScrnInfoPtr pScrn, Bool canGrow);
 
 void
 xf86DPMSSet(ScrnInfoPtr pScrn, int PowerManagementMode, int flags);