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>

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

drivers/gpu/drm/i915/intel_lvds.c

@@ -953,6 +953,8 @@ void intel_lvds_init(struct drm_device *dev)
 
 	intel_encoder->clone_mask = (1 << INTEL_LVDS_CLONE_BIT);
 	intel_encoder->crtc_mask = (1 << 1);
+	if (IS_I965G(dev))
+		intel_encoder->crtc_mask |= (1 << 0);
 	drm_encoder_helper_add(encoder, &intel_lvds_helper_funcs);
 	drm_connector_helper_add(connector, &intel_lvds_connector_helper_funcs);
 	connector->display_info.subpixel_order = SubPixelHorizontalRGB;