drm/i915: Set the LVDS_BORDER when using LVDS scaling mode

According to the spec the LVDS_BORDER_ENABLE bit decides whether the border
data should be included in the active display and data sent to the panel.
Border should be used when in VGA centered (un-scaled) mode or when scaling
a 4:3 source image to a wide screen panel (typical 16:9).

So when the LVDS scaling is used, decide whether the LVDS_BORDER should be
enabled or not according to the current scaling mode.

At the same time fix the typo error in LVDS center scaling mode.

https://bugs.freedesktop.org/show_bug.cgi?id=23789

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
tested-by: Zhao Jian <jian.zhao@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

4 files changed, 15 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 0094f185e17d..17be01e351b3 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -492,6 +492,8 @@ typedef struct drm_i915_private {
                 struct drm_i915_gem_phys_object *phys_objs[I915_MAX_PHYS_OBJECT];
         } mm;
         struct sdvo_device_mapping sdvo_mappings[2];
+        /* indicate whether the LVDS_BORDER should be enabled or not */
+        unsigned int lvds_border_bits;
 
         /* Reclocking support */
         bool render_reclock_avail;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 0466ddbeba32..5f9272459b71 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -968,6 +968,8 @@
 #define   LVDS_PORT_EN                  (1 << 31)
 /* Selects pipe B for LVDS data.  Must be set on pre-965. */
 #define   LVDS_PIPEB_SELECT             (1 << 30)
+/* Enable border for unscaled (or aspect-scaled) display */
+#define   LVDS_BORDER_ENABLE            (1 << 15)
 /*
  * Enables the A0-A2 data pairs and CLKA, containing 18 bits of color data per
  * pixel.
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 3c14240cc002..9efe11761be3 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2936,6 +2936,8 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,
 
                 lvds = I915_READ(lvds_reg);
                 lvds |= LVDS_PORT_EN | LVDS_A0A2_CLKA_POWER_UP | LVDS_PIPEB_SELECT;
+                /* set the corresponsding LVDS_BORDER bit */
+                lvds |= dev_priv->lvds_border_bits;
                 /* Set the B0-B3 data pairs corresponding to whether we're going to
                  * set the DPLLs for dual-channel mode or not.
                  */
diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index 98ae3d73577e..089f18c66ddb 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -380,7 +380,7 @@ static bool intel_lvds_mode_fixup(struct drm_encoder *encoder,
                                 adjusted_mode->crtc_vblank_start + vsync_pos;
                 /* keep the vsync width constant */
                 adjusted_mode->crtc_vsync_end =
-                                adjusted_mode->crtc_vblank_start + vsync_width;
+                                adjusted_mode->crtc_vsync_start + vsync_width;
                 border = 1;
                 break;
         case DRM_MODE_SCALE_ASPECT:
@@ -526,6 +526,14 @@ out:
         lvds_priv->pfit_control = pfit_control;
         lvds_priv->pfit_pgm_ratios = pfit_pgm_ratios;
         /*
+         * When there exists the border, it means that the LVDS_BORDR
+         * should be enabled.
+         */
+        if (border)
+                dev_priv->lvds_border_bits |= LVDS_BORDER_ENABLE;
+        else
+                dev_priv->lvds_border_bits &= ~(LVDS_BORDER_ENABLE);
+        /*
          * XXX: It would be nice to support lower refresh rates on the
          * panels to reduce power consumption, and perhaps match the
          * user's requested refresh rate.