[PATCH v2 0/3] add LG panel to dpcd quirk database

[Lee, Shawn C]

On Mon, Sep 10, 2018 at 10:55 AM Alex Deucher wrote:
>>
>> Only specific N value (0x8000) would be acceptable for LG
>> LP140WF6-SPM1 eDP panel which is running at asynchronous clock mode. 
>> With the other N value, it will enter BITS mode and display black 
>> screen. This patch series set constant N value for specific 
>> sink/branch device that would cover similar issue.
>
>Is this an explicit requirement of the panel itself or just a workaround for for a PLL limitation on a particular GPU?  For example, due to hw design and electrical characteristics, certain divider combinations may not be viable on certain asics.  If that's the case, shouldn't this be handled in an asic specific manor?  If it's a requirement of the panel itself, ignore me and carry on.
>
>Alex
>

This is a special requirement that panel's tcon ask a particular value of N divider. Tcon needs this value for internal configuration.

>>
>> Cc: Jani Nikula <jani.nikula at intel.com>
>> Cc: Cooper Chiou <cooper.chiou at intel.com>
>> Cc: Matt Atwood <matthew.s.atwood at intel.com>
>> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
>> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
>> Cc: Clint Taylor <clinton.a.taylor at intel.com>
>>
>> Lee, Shawn C (3):
>>   drm: Add support for device_id based detection.
>>   drm: Change limited M/N quirk to constant N quirk.
>>   drm: add LG eDP panel to quirk database
>>
>>  drivers/gpu/drm/drm_dp_helper.c      | 17 ++++++++++++++++-
>>  drivers/gpu/drm/i915/intel_display.c | 28 
>> +++++++++++++---------------  drivers/gpu/drm/i915/intel_display.h |  2 +-
>>  drivers/gpu/drm/i915/intel_dp.c      |  8 ++++----
>>  drivers/gpu/drm/i915/intel_dp_mst.c  |  6 +++---
>>  include/drm/drm_dp_helper.h          |  6 +++---
>>  6 files changed, 40 insertions(+), 27 deletions(-)
>>
>> --
>> 2.7.4
>>
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