<html>
    <head>
      <base href="https://bugs.freedesktop.org/">
    </head>
    <body>
      <p>
        <div>
            <b><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - [bisected] GDM Login screen doesn't show up on kernel 5.3 or later"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=111966#c6">Comment # 6</a>
              on <a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - [bisected] GDM Login screen doesn't show up on kernel 5.3 or later"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=111966">bug 111966</a>
              from <span class="vcard"><a class="email" href="mailto:masami256@gmail.com" title="Masami Ichikawa <masami256@gmail.com>"> <span class="fn">Masami Ichikawa</span></a>
</span></b>
        <pre>I made quick hack. following patch works fine for me on mainline kernel
5.4-rc2.


diff --git a/drivers/gpu/drm/i915/display/intel_bios.c
b/drivers/gpu/drm/i915/display/intel_bios.c
index efb39f350b19..c886dae82aa7 100644
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -1313,6 +1313,8 @@ static void sanitize_aux_ch(struct drm_i915_private
*dev_priv,

        p = get_port_by_aux_ch(dev_priv, info->alternate_aux_channel);
        if (p != PORT_NONE) {
+               info = &dev_priv->vbt.ddi_port_info[p];
+
                DRM_DEBUG_KMS("port %c trying to use the same AUX CH (0x%x) as
port %c, "
                              "disabling port %c DP support\n",
                              port_name(port), info->alternate_aux_channel,
@@ -1330,6 +1332,7 @@ static void sanitize_aux_ch(struct drm_i915_private
*dev_priv,
                info->supports_dp = false;
                info->alternate_aux_channel = 0;
        }
+
 }

 static const u8 cnp_ddc_pin_map[] = {</pre>
        </div>
      </p>


      <hr>
      <span>You are receiving this mail because:</span>

      <ul>
          <li>You are the assignee for the bug.</li>
          <li>You are the QA Contact for the bug.</li>
          <li>You are on the CC list for the bug.</li>
      </ul>
    </body>
</html>