--- linux-2.4.24/drivers/video/aty/atyfb_base.c.orig	2003-11-28 20:26:20.000000000 +0200
+++ linux-2.4.24/drivers/video/aty/atyfb_base.c	2004-02-10 20:15:15.000000000 +0200
@@ -1475,6 +1475,8 @@
 
     xres = (((par->crtc.h_tot_disp>>16) & 0xff)+1)*8;
     yres = ((par->crtc.v_tot_disp>>16) & 0x7ff)+1;
+    if (par->crtc.gen_cntl & CRTC_DBL_SCAN_EN)
+        yres >>= 1;
     xoffset = (var->xoffset+7) & ~7;
     yoffset = var->yoffset;
     if (xoffset+xres > par->crtc.vxres || yoffset+yres > par->crtc.vyres)