drm/i915: Allow LVDS on pipe A on gen4+

The gen4 docs say it works, so why not.  Tested on Ironlake.

Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 5a6980082064..eb4a265861ec 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3303,7 +3303,9 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,
                         lvds_reg = PCH_LVDS;
 
                 lvds = I915_READ(lvds_reg);
-                lvds |= LVDS_PORT_EN | LVDS_A0A2_CLKA_POWER_UP | LVDS_PIPEB_SELECT;
+                lvds |= LVDS_PORT_EN | LVDS_A0A2_CLKA_POWER_UP;
+                if (pipe == 1)
+                        lvds |= 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