diff --git a/drivers/video/omap2/dss/hdmi.c b/drivers/video/omap2/dss/hdmi.c
index 52731b5e10f0cc7d0cac69ae37e68897d6cdc09e..4752137b226ac84f64a3548f5663973e992c59ca 100644
--- a/drivers/video/omap2/dss/hdmi.c
+++ b/drivers/video/omap2/dss/hdmi.c
@@ -60,7 +60,7 @@
 
 #define OMAP_HDMI_TIMINGS_NB			34
 
-#define HDMI_DEFAULT_REGN 15
+#define HDMI_DEFAULT_REGN 16
 #define HDMI_DEFAULT_REGM2 1
 
 static struct {
@@ -426,7 +426,7 @@ static void hdmi_compute_pll(struct omap_dss_device *dssdev, int phy,
 	else
 		pi->regn = dssdev->clocks.hdmi.regn;
 
-	refclk = clkin / (pi->regn + 1);
+	refclk = clkin / pi->regn;
 
 	/*
 	 * multiplier is pixel_clk/ref_clk
@@ -452,7 +452,7 @@ static void hdmi_compute_pll(struct omap_dss_device *dssdev, int phy,
 	 * is greater than 1000MHz
 	 */
 	pi->dcofreq = phy > 1000 * 100;
-	pi->regsd = ((pi->regm * clkin / 10) / ((pi->regn + 1) * 250) + 5) / 10;
+	pi->regsd = ((pi->regm * clkin / 10) / (pi->regn * 250) + 5) / 10;
 
 	/* Set the reference clock to sysclk reference */
 	pi->refsel = HDMI_REFSEL_SYSCLK;
diff --git a/drivers/video/omap2/dss/ti_hdmi_4xxx_ip.c b/drivers/video/omap2/dss/ti_hdmi_4xxx_ip.c
index cb3a2d6753de993449381622b9873ff3ef9ce09f..403c662414778a295732888dcffeffff88ef8398 100644
--- a/drivers/video/omap2/dss/ti_hdmi_4xxx_ip.c
+++ b/drivers/video/omap2/dss/ti_hdmi_4xxx_ip.c
@@ -92,7 +92,7 @@ static int hdmi_pll_init(struct hdmi_ip_data *ip_data)
 
 	r = hdmi_read_reg(pll_base, PLLCTRL_CFG1);
 	r = FLD_MOD(r, fmt->regm, 20, 9); /* CFG1_PLL_REGM */
-	r = FLD_MOD(r, fmt->regn, 8, 1);  /* CFG1_PLL_REGN */
+	r = FLD_MOD(r, fmt->regn - 1, 8, 1);  /* CFG1_PLL_REGN */
 
 	hdmi_write_reg(pll_base, PLLCTRL_CFG1, r);
 
diff --git a/include/video/omapdss.h b/include/video/omapdss.h
index 44f423ff64bd9b4e8e7a1790043183f8557fa39c..c7cfdad812422847d32bb3f5915f9f5030c38788 100644
--- a/include/video/omapdss.h
+++ b/include/video/omapdss.h
@@ -520,6 +520,7 @@ struct omap_dss_device {
 		} dsi;
 
 		struct {
+			/* regn is one greater than TRM's REGN value */
 			u16 regn;
 			u16 regm2;
 		} hdmi;