drm/i915: Refuse modes with hdisplay==4096 on pre-HSW DP

	return 0;

}

static bool intel_dp_hdisplay_bad(struct drm_i915_private *dev_priv,

				  int hdisplay)

{

	/*

	 * Older platforms don't like hdisplay==4096 with DP.

	 *

	 * On ILK/SNB/IVB the pipe seems to be somewhat running (scanline

	 * and frame counter increment), but we don't get vblank interrupts,

	 * and the pipe underruns immediately. The link also doesn't seem

	 * to get trained properly.

	 *

	 * On CHV the vblank interrupts don't seem to disappear but

	 * otherwise the symptoms are similar.

	 *

	 * TODO: confirm the behaviour on HSW+

	 */

	return hdisplay == 4096 && !HAS_DDI(dev_priv);

}

static enum drm_mode_status

intel_dp_mode_valid(struct drm_connector *connector,

		    struct drm_display_mode *mode)

	max_rate = intel_dp_max_data_rate(max_link_clock, max_lanes);

	mode_rate = intel_dp_link_required(target_clock, 18);

	if (intel_dp_hdisplay_bad(dev_priv, mode->hdisplay))

		return MODE_H_ILLEGAL;

	/*

	 * Output bpp is stored in 6.4 format so right shift by 4 to get the

	 * integer value since we support only integer values of bpp.

	if (adjusted_mode->flags & DRM_MODE_FLAG_DBLCLK)

		return -EINVAL;

	if (intel_dp_hdisplay_bad(dev_priv, adjusted_mode->crtc_hdisplay))

		return -EINVAL;

	ret = intel_dp_compute_link_config(encoder, pipe_config, conn_state);

	if (ret < 0)

		return ret;