viafb: initialize margins correct

This patch initializes the margins for the initial mode correct.
This is required to get the desired initial refresh rate. Also do
more verbose sanity checking to prevent misbehavior.

Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
diff --git a/drivers/video/via/viafbdev.c b/drivers/video/via/viafbdev.c
index fd6a15f..9d9bb9b 100644
--- a/drivers/video/via/viafbdev.c
+++ b/drivers/video/via/viafbdev.c
@@ -1806,14 +1806,9 @@
 	default_var.xres_virtual = default_xres;
 	default_var.yres_virtual = default_yres;
 	default_var.bits_per_pixel = viafb_bpp;
-	default_var.pixclock =
-	    viafb_get_pixclock(default_xres, default_yres, viafb_refresh);
-	default_var.left_margin = (default_xres >> 3) & 0xf8;
-	default_var.right_margin = 32;
-	default_var.upper_margin = 16;
-	default_var.lower_margin = 4;
-	default_var.hsync_len = default_var.left_margin;
-	default_var.vsync_len = 4;
+	viafb_fill_var_timing_info(&default_var, viafb_get_refresh(
+		default_var.xres, default_var.yres, viafb_refresh),
+		viafb_get_mode(default_var.xres, default_var.yres));
 	viafb_setup_fixinfo(&viafbinfo->fix, viaparinfo);
 	viafbinfo->var = default_var;
 
@@ -1852,15 +1847,9 @@
 		default_var.xres_virtual = viafb_second_virtual_xres;
 		default_var.yres_virtual = viafb_second_virtual_yres;
 		default_var.bits_per_pixel = viafb_bpp1;
-		default_var.pixclock =
-		    viafb_get_pixclock(viafb_second_xres, viafb_second_yres,
-		    viafb_refresh1);
-		default_var.left_margin = (viafb_second_xres >> 3) & 0xf8;
-		default_var.right_margin = 32;
-		default_var.upper_margin = 16;
-		default_var.lower_margin = 4;
-		default_var.hsync_len = default_var.left_margin;
-		default_var.vsync_len = 4;
+		viafb_fill_var_timing_info(&default_var, viafb_get_refresh(
+			default_var.xres, default_var.yres, viafb_refresh1),
+			viafb_get_mode(default_var.xres, default_var.yres));
 
 		viafb_setup_fixinfo(&viafbinfo1->fix, viaparinfo1);
 		viafb_check_var(&default_var, viafbinfo1);
@@ -2015,15 +2004,17 @@
  */
 int __init viafb_init(void)
 {
-	u32 dummy;
+	u32 dummy_x, dummy_y;
 #ifndef MODULE
 	char *option = NULL;
 	if (fb_get_options("viafb", &option))
 		return -ENODEV;
 	viafb_setup(option);
 #endif
-	if (parse_mode(viafb_mode, &dummy, &dummy)
-		|| parse_mode(viafb_mode1, &dummy, &dummy)
+	if (parse_mode(viafb_mode, &dummy_x, &dummy_y)
+		|| !viafb_get_mode(dummy_x, dummy_y)
+		|| parse_mode(viafb_mode1, &dummy_x, &dummy_y)
+		|| !viafb_get_mode(dummy_x, dummy_y)
 		|| viafb_bpp < 0 || viafb_bpp > 32
 		|| viafb_bpp1 < 0 || viafb_bpp1 > 32
 		|| parse_active_dev())