1 files changed, 12 insertions, 7 deletions

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
index b5b865f4f92b..086e52af1bc7 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
@@ -289,17 +289,22 @@ static int tilcdc_crtc_mode_set(struct drm_crtc *crtc,
         reg = tilcdc_read(dev, LCDC_RASTER_TIMING_2_REG) & ~0x000fff00;
         reg |= LCDC_AC_BIAS_FREQUENCY(info->ac_bias) |
                 LCDC_AC_BIAS_TRANSITIONS_PER_INT(info->ac_bias_intrpt);
+
+        /*
+         * subtract one from hfp, hbp, hsw because the hardware uses
+         * a value of 0 as 1
+         */
         if (priv->rev == 2) {
-                reg |= (hfp & 0x300) >> 8;
-                reg |= (hbp & 0x300) >> 4;
-                reg |= (hsw & 0x3c0) << 21;
+                reg |= ((hfp-1) & 0x300) >> 8;
+                reg |= ((hbp-1) & 0x300) >> 4;
+                reg |= ((hsw-1) & 0x3c0) << 21;
         }
         tilcdc_write(dev, LCDC_RASTER_TIMING_2_REG, reg);
 
         reg = (((mode->hdisplay >> 4) - 1) << 4) |
-                ((hbp & 0xff) << 24) |
-                ((hfp & 0xff) << 16) |
-                ((hsw & 0x3f) << 10);
+                (((hbp-1) & 0xff) << 24) |
+                (((hfp-1) & 0xff) << 16) |
+                (((hsw-1) & 0x3f) << 10);
         if (priv->rev == 2)
                 reg |= (((mode->hdisplay >> 4) - 1) & 0x40) >> 3;
         tilcdc_write(dev, LCDC_RASTER_TIMING_0_REG, reg);
@@ -307,7 +312,7 @@ static int tilcdc_crtc_mode_set(struct drm_crtc *crtc,
         reg = ((mode->vdisplay - 1) & 0x3ff) |
                 ((vbp & 0xff) << 24) |
                 ((vfp & 0xff) << 16) |
-                ((vsw & 0x3f) << 10);
+                (((vsw-1) & 0x3f) << 10);
         tilcdc_write(dev, LCDC_RASTER_TIMING_1_REG, reg);
 
         /*