diff --git a/drivers/video/fbdev/aty/atyfb.h b/drivers/video/fbdev/aty/atyfb.h
index 8235b285dbb2..d09bab3bf224 100644
--- a/drivers/video/fbdev/aty/atyfb.h
+++ b/drivers/video/fbdev/aty/atyfb.h
@@ -333,6 +333,8 @@ extern const struct aty_pll_ops aty_pll_ct; /* Integrated */
 extern void aty_set_pll_ct(const struct fb_info *info, const union aty_pll *pll);
 extern u8 aty_ld_pll_ct(int offset, const struct atyfb_par *par);
 
+extern const u8 aty_postdividers[8];
+
 
     /*
      *  Hardware cursor support
@@ -359,7 +361,6 @@ static inline void wait_for_idle(struct atyfb_par *par)
 
 extern void aty_reset_engine(const struct atyfb_par *par);
 extern void aty_init_engine(struct atyfb_par *par, struct fb_info *info);
-extern u8   aty_ld_pll_ct(int offset, const struct atyfb_par *par);
 
 void atyfb_copyarea(struct fb_info *info, const struct fb_copyarea *area);
 void atyfb_fillrect(struct fb_info *info, const struct fb_fillrect *rect);
diff --git a/drivers/video/fbdev/aty/atyfb_base.c b/drivers/video/fbdev/aty/atyfb_base.c
index a9a8272f7a6e..05111e90f168 100644
--- a/drivers/video/fbdev/aty/atyfb_base.c
+++ b/drivers/video/fbdev/aty/atyfb_base.c
@@ -3087,17 +3087,18 @@ static int atyfb_setup_sparc(struct pci_dev *pdev, struct fb_info *info,
 		/*
 		 * PLL Reference Divider M:
 		 */
-		M = pll_regs[2];
+		M = pll_regs[PLL_REF_DIV];
 
 		/*
 		 * PLL Feedback Divider N (Dependent on CLOCK_CNTL):
 		 */
-		N = pll_regs[7 + (clock_cntl & 3)];
+		N = pll_regs[VCLK0_FB_DIV + (clock_cntl & 3)];
 
 		/*
 		 * PLL Post Divider P (Dependent on CLOCK_CNTL):
 		 */
-		P = 1 << (pll_regs[6] >> ((clock_cntl & 3) << 1));
+		P = aty_postdividers[((pll_regs[VCLK_POST_DIV] >> ((clock_cntl & 3) << 1)) & 3) |
+		                     ((pll_regs[PLL_EXT_CNTL] >> (2 + (clock_cntl & 3))) & 4)];
 
 		/*
 		 * PLL Divider Q:
diff --git a/drivers/video/fbdev/aty/mach64_ct.c b/drivers/video/fbdev/aty/mach64_ct.c
index 74a62aa193c0..f87cc81f4fa2 100644
--- a/drivers/video/fbdev/aty/mach64_ct.c
+++ b/drivers/video/fbdev/aty/mach64_ct.c
@@ -115,7 +115,7 @@ static void aty_st_pll_ct(int offset, u8 val, const struct atyfb_par *par)
  */
 
 #define Maximum_DSP_PRECISION 7
-static u8 postdividers[] = {1,2,4,8,3};
+const u8 aty_postdividers[8] = {1,2,4,8,3,5,6,12};
 
 static int aty_dsp_gt(const struct fb_info *info, u32 bpp, struct pll_ct *pll)
 {
@@ -222,7 +222,7 @@ static int aty_valid_pll_ct(const struct fb_info *info, u32 vclk_per, struct pll
 		pll->vclk_post_div += (q <  64*8);
 		pll->vclk_post_div += (q <  32*8);
 	}
-	pll->vclk_post_div_real = postdividers[pll->vclk_post_div];
+	pll->vclk_post_div_real = aty_postdividers[pll->vclk_post_div];
 	//    pll->vclk_post_div <<= 6;
 	pll->vclk_fb_div = q * pll->vclk_post_div_real / 8;
 	pllvclk = (1000000 * 2 * pll->vclk_fb_div) /
@@ -513,7 +513,7 @@ static int aty_init_pll_ct(const struct fb_info *info, union aty_pll *pll)
 		u8 mclk_fb_div, pll_ext_cntl;
 		pll->ct.pll_ref_div = aty_ld_pll_ct(PLL_REF_DIV, par);
 		pll_ext_cntl = aty_ld_pll_ct(PLL_EXT_CNTL, par);
-		pll->ct.xclk_post_div_real = postdividers[pll_ext_cntl & 0x07];
+		pll->ct.xclk_post_div_real = aty_postdividers[pll_ext_cntl & 0x07];
 		mclk_fb_div = aty_ld_pll_ct(MCLK_FB_DIV, par);
 		if (pll_ext_cntl & PLL_MFB_TIMES_4_2B)
 			mclk_fb_div <<= 1;
@@ -535,7 +535,7 @@ static int aty_init_pll_ct(const struct fb_info *info, union aty_pll *pll)
 		xpost_div += (q <  64*8);
 		xpost_div += (q <  32*8);
 	}
-	pll->ct.xclk_post_div_real = postdividers[xpost_div];
+	pll->ct.xclk_post_div_real = aty_postdividers[xpost_div];
 	pll->ct.mclk_fb_div = q * pll->ct.xclk_post_div_real / 8;
 
 #ifdef CONFIG_PPC
@@ -584,7 +584,7 @@ static int aty_init_pll_ct(const struct fb_info *info, union aty_pll *pll)
 			mpost_div += (q <  64*8);
 			mpost_div += (q <  32*8);
 		}
-		sclk_post_div_real = postdividers[mpost_div];
+		sclk_post_div_real = aty_postdividers[mpost_div];
 		pll->ct.sclk_fb_div = q * sclk_post_div_real / 8;
 		pll->ct.spll_cntl2 = mpost_div << 4;
 #ifdef DEBUG