drm/i915/bios: ignore HDMI on port A

The hardware state readout oopses after several warnings when trying to
use HDMI on port A, if such a combination is configured in VBT. Filter
the combo out already at the VBT parsing phase.

v2: also ignore DVI (Ville)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102889
Cc: stable@vger.kernel.org
Cc: Imre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: NDaniel Drake <dan@reactivated.net>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170921141920.18172-1-jani.nikula@intel.com

drivers/gpu/drm/i915/intel_bios.c

@@ -1163,6 +1163,13 @@ static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,
 	is_hdmi = is_dvi && (child->device_type & DEVICE_TYPE_NOT_HDMI_OUTPUT) == 0;
 	is_edp = is_dp && (child->device_type & DEVICE_TYPE_INTERNAL_CONNECTOR);
 
+	if (port == PORT_A && is_dvi) {
+		DRM_DEBUG_KMS("VBT claims port A supports DVI%s, ignoring\n",
+			      is_hdmi ? "/HDMI" : "");
+		is_dvi = false;
+		is_hdmi = false;
+	}
+
 	info->supports_dvi = is_dvi;
 	info->supports_hdmi = is_hdmi;
 	info->supports_dp = is_dp;