<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_REOPENED " title="REOPENED - Black/blank screen at boot (last message line: fb: switching to inteldrmfb from EFI VGA) unless i915.modeset=0 is set" href="https://bugs.freedesktop.org/show_bug.cgi?id=105549#c27">Comment # 27</a> on <a class="bz_bug_link bz_status_REOPENED " title="REOPENED - Black/blank screen at boot (last message line: fb: switching to inteldrmfb from EFI VGA) unless i915.modeset=0 is set" href="https://bugs.freedesktop.org/show_bug.cgi?id=105549">bug 105549</a> from <a class="email" href="mailto:jani.nikula@intel.com" title="Jani Nikula <jani.nikula@intel.com>"> Jani Nikula</a> <pre>Okay, I have a hunch. I assume you all 1) have a Dell Latitude 5490 or thereabouts, 2) you all have a Kabylake (KBL) system with either Sunrisepoint PCH (SPT) or Kabylake PCH (KBP), and 3) the problems started after updating the BIOS. Please check your dmesg with drm.debug=14 set, and look for lines similar to these: [ 35.431169] [drm:intel_pch_type [i915]] Found SunrisePoint LP PCH [ 35.456889] i915 device info: pciid=0x5917 rev=0x07 platform=KABYLAKE gen=9 There are KBL systems with SPT and KBP, but there are *also* newer KBL systems with Cannonlake PCH (CPT). The way the VBT is specified, we need to do some mapping on the DDC pin on CPT. The mapping would be right for CPT, but wrong for SPT and KBP. Now, I presume Dell has inadvertently based their BIOS update on the newer model's BIOS, without taking this into account. It would really be useful to get the VBT dumps before and after BIOS update. Can you downgrade the BIOS?</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are the assignee for the bug.</li> <li>You are on the CC list for the bug.</li> </ul> </body> </html>