[Bug 100755] [HSW] linux next-20170407+ boots to a blank screen

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=100755

--- Comment #2 from Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com> ---
The link m_n and data m_n values are different before and after suspend/resume.
My hunch is when you booted with fastboot=1, commit[1] did not reduce data m_n
but did so after suspend/resume.

Before:
[drm:intel_dump_pipe_config] dp m_n: lanes: 2; gmch_m: 2428257, gmch_n:
8388608, link_m: 134903, link_n: 524288, tu: 64

After:
[drm:intel_dump_pipe_config] dp m_n: lanes: 2; gmch_m: 302776, gmch_n: 1048576,
link_m: 33641, link_n: 131072, tu: 64


Try reverting this - 

commit 9a86cda07af2c63649932f0a4fc757701ef54c42
Author: Jani Nikula <jani.nikula at intel.com>
Date:   Mon Mar 27 14:33:25 2017 +0300

    drm/i915/dp: reduce link M/N parameters

    Several major vendor USB-C->HDMI converters, in particular the DA200,
    fail to recover a 5.4 GHz 1 lane signal if the link N is greater than
    0x80000.

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