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

2018-09-10 Thread 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 
>> Cc: Cooper Chiou 
>> Cc: Matt Atwood 
>> Cc: Maarten Lankhorst 
>> Cc: Dhinakaran Pandiyan 
>> Cc: Clint Taylor 
>>
>> 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
>>
>> ___
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
___
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel


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

2018-09-10 Thread Alex Deucher
On Mon, Sep 10, 2018 at 10:55 AM Lee, Shawn C  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

>
> Cc: Jani Nikula 
> Cc: Cooper Chiou 
> Cc: Matt Atwood 
> Cc: Maarten Lankhorst 
> Cc: Dhinakaran Pandiyan 
> Cc: Clint Taylor 
>
> 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
>
> ___
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
___
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel


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

2018-09-10 Thread Lee, Shawn C
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.

Cc: Jani Nikula 
Cc: Cooper Chiou 
Cc: Matt Atwood 
Cc: Maarten Lankhorst 
Cc: Dhinakaran Pandiyan 
Cc: Clint Taylor 

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

___
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel