[Intel-gfx] [PATCH] drm: Fix for invalid pruning of modes in dual display cases

[Jani Nikula]

On Tue, 13 Dec 2016, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> On Tue, Dec 13, 2016 at 03:46:54PM +0530, Vidya Srinivas wrote:
>> Currently in dual display connected boot scenarios, minimum of the resolutions
>> is taken for fb width and height as reference. Based on this resolution, other
>> modes are pruned.
>> 
>> Example Scenario: If DSI mode is 2560x1440 and HDMI is 1920x1080, during the probing
>> the fb width and height is set to max 1920x1080 and the DSI mode gets pruned as it is
>> more than the reference. As a result, there is no DSI display.
>> Patch fixes this issue by taking the max of the resolutions and creating the fb
>> based on the same.
>
> On the other hand, the viewable content is defined by the smaller mode.
> If that is the only output visible at panic time, you don't want that
> information lost due to it being invisible.
>
> This is only used for fbcon, which has to be the lowest common
> denominator. Any actual application can set their own modes and fb.

Do we fail to take over non-native modes with scaling on DSI then?
Ville?

BR,
Jani.


-- 
Jani Nikula, Intel Open Source Technology Center