[Intel-gfx] [PATCH 6/6] drm/i915: fix VGA detect on IGDNG

[Barry Scott]

Keith Packard wrote:
> On Tue, 2009-07-28 at 15:11 +0800, Zhenyu Wang wrote:
>
>   
>> This introduces screen flicker which is bad, more testing takes
>> me to below patch. Force detection on IGDNG desktop chip seems
>> doesn't require disable DAC first, but mobile chip has trouble
>> with that, so I just fallback to DDC probe instead. Any comment?
>>     
>
> We can't require DDC on VGA; monitor switches often do not pass DDC
> along. The only reliable way to detect VGA monitors is load detection.
>
>   
Also you do not get DDC with a screen connected with a VGA-over-CAT5
solution.

Barry