From mboxrd@z Thu Jan  1 00:00:00 1970
From: Paul Bolle <pebolle@tiscali.nl>
Subject: drm/i915: "Wrong MCH_SSKPD value: 0x16040307"
Date: Wed, 30 Jul 2014 20:49:07 +0200
Message-ID: <1406746147.2406.50.camel@x220>
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To: Daniel Vetter <daniel.vetter@ffwll.ch>, Jani Nikula <jani.nikula@linux.intel.com>, David Airlie <airlied@linux.ie>
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0) A ThinkPad X220 I use prints these messages at every boot and at
every resume:
    [drm] Wrong MCH_SSKPD value: 0x16040307
    [drm] This can cause pipe underruns and display issues.
    [drm] Please upgrade your BIOS to fix this.

These messages can be seen for every kernel that's still in the logs
(the oldest is v3.11 based).

1) I'm not sure whether I actually run into "pipe underruns" or "display
issues". Is there something specific I should look for?

2) Now it happens that this laptop already runs the latest BIOS. So, if
I were to contact Lenovo to see if they could release a BIOS update to
fix this, what should I ask them to do?


Paul Bolle