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

[Chris Wilson]

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.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre