--- xc/programs/Xserver/hw/xfree86/drivers/ati/radeon_driver.c.orig	2005-07-28 09:58:30.026778717 -0400
+++ xc/programs/Xserver/hw/xfree86/drivers/ati/radeon_driver.c	2005-07-28 10:02:23.136972800 -0400
@@ -1994,7 +2004,7 @@ RADEONSetFBLocation(ScrnInfoPtr pScrn)
     unsigned char *RADEONMMIO = info->MMIO;
     CARD32 mc_fb_location;
     CARD32 mc_agp_location = INREG(RADEON_MC_AGP_LOCATION);
-
+    CARD32 crtc_ext_cntl, crtc_gen_cntl, crtc2_gen_cntl=0, ov0_scale_cntl;

     /* This function has many problems with newer cards.
      * Even with older cards, all registers changed here are not
@@ -2047,12 +2057,40 @@ RADEONSetFBLocation(ScrnInfoPtr pScrn)

     RADEONWaitForIdleMMIO(pScrn);

+    /* Stop display & memory access */
+    crtc_ext_cntl = INREG(RADEON_CRTC_EXT_CNTL);
+    OUTREG(RADEON_CRTC_EXT_CNTL, crtc_ext_cntl | RADEON_CRTC_DISPLAY_DIS);
+    crtc_gen_cntl = INREG(RADEON_CRTC_GEN_CNTL);
+    OUTREG(RADEON_CRTC_GEN_CNTL, (crtc_gen_cntl & ~RADEON_CRTC_CUR_EN) |
+                                 RADEON_CRTC_DISP_REQ_EN_B);
+    if (info->HasCRTC2) {
+       crtc2_gen_cntl = INREG(RADEON_CRTC2_GEN_CNTL);
+       OUTREG(RADEON_CRTC2_GEN_CNTL, (crtc2_gen_cntl & ~RADEON_CRTC2_CUR_EN) |
+                                     RADEON_CRTC2_DISP_REQ_EN_B);
+    }
+    ov0_scale_cntl = INREG(RADEON_OV0_SCALE_CNTL);
+    OUTREG(RADEON_OV0_SCALE_CNTL, ov0_scale_cntl & ~RADEON_SCALER_ENABLE);
+
+    /* Make sure the chip settles down and set new map*/
+    usleep(100000);
+
     OUTREG(RADEON_MC_FB_LOCATION, mc_fb_location);
     OUTREG(RADEON_MC_AGP_LOCATION, mc_agp_location);
+
+    /* Make sure map fully reached the chip */
+    (void)INREG(RADEON_MC_FB_LOCATION);
+
     OUTREG(RADEON_DISPLAY_BASE_ADDR, info->fbLocation);
     if (info->HasCRTC2)
 	OUTREG(RADEON_DISPLAY2_BASE_ADDR, info->fbLocation);
     OUTREG(RADEON_OV0_BASE_ADDR, info->fbLocation);
+
+    /* Restore display & memory access */
+    OUTREG(RADEON_CRTC_EXT_CNTL, crtc_ext_cntl);
+    OUTREG(RADEON_CRTC_GEN_CNTL, crtc_gen_cntl);
+    if (info->HasCRTC2)
+       OUTREG(RADEON_CRTC2_GEN_CNTL, crtc2_gen_cntl);
+    OUTREG(RADEON_OV0_SCALE_CNTL, ov0_scale_cntl);
 }

 static void RADEONGetVRamType(ScrnInfoPtr pScrn)