drm/i915: Reject >165MHz modes w/ DVI monitors

Single-link DVI max dotclock is 165MHz. Filter out modes with higher
dotclock when the monitor doesn't support HDMI.

Modes higher than 165 MHz were allowed in

commit 7d148ef5
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Mon Jul 22 18:02:39 2013 +0200

    drm/i915: fix hdmi portclock limits

Also don't attempt to use 12bpc mode with DVI monitors.

Cc: Adam Nielsen <a.nielsen@shikadi.net>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=75345
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=70331Tested-by: NRalf Jung <post+kernel@ralfj.de>
Cc: stable@vger.kernel.org
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/intel_hdmi.c

@@ -845,7 +845,7 @@ static int hdmi_portclock_limit(struct intel_hdmi *hdmi)
 {
 	struct drm_device *dev = intel_hdmi_to_dev(hdmi);
 
-	if (IS_G4X(dev))
+	if (!hdmi->has_hdmi_sink || IS_G4X(dev))
 		return 165000;
 	else if (IS_HASWELL(dev) || INTEL_INFO(dev)->gen >= 8)
 		return 300000;
@@ -899,8 +899,8 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
 	 * outputs. We also need to check that the higher clock still fits
 	 * within limits.
 	 */
-	if (pipe_config->pipe_bpp > 8*3 && clock_12bpc <= portclock_limit
-	    && HAS_PCH_SPLIT(dev)) {
+	if (pipe_config->pipe_bpp > 8*3 && intel_hdmi->has_hdmi_sink &&
+	    clock_12bpc <= portclock_limit && HAS_PCH_SPLIT(dev)) {
 		DRM_DEBUG_KMS("picking bpc to 12 for HDMI output\n");
 		desired_bpp = 12*3;