[Intel-gfx] Why Baytrail Gfx driver not always uses pipe A when it's free?

[Jesse Barnes]

No special reason.  It shouldn't matter on BYT either, really, since
pipe A doesn't have special characteristics like it does on HSW.

Jesse

On Thu, 6 Mar 2014 17:19:22 +0800
"Lin, Mengdong" <mengdong.lin at intel.com> wrote:

> Hi Jesse,
> 
>  
> 
> Could you tell us why Baytrail Gfx driver does not always use pipe A when it's free?
> 
>  
> 
> We have a Baytrail-M which only have HDMI (port B) and DisplayPort (port C) output.
> 
> When I connect HDMI or DP only, the Gfx driver always uses pipe B for port B/C, although pipe A is free. This behavior does not change no matter I enable X or not.
> 
> Is there any special consideration?
> 
>  
> 
> This is different from what we observe on HSW/BDW, where pipe A is always used if it’s free.
> 
>  
> 
> Thanks
> 
> Mengdong