Re: Request for feedback : [RFC] Added a new 'window size' property for connector

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Fri, Mar 07, 2014 at 12:45:26PM +0000, Goel, Akash wrote:
> Thanks for your feedback.
> 
> > No, fb_id is passed through setcrtc (or soon through setplane, I hope).
> Actually mentioned 'fb_id' also, because if PIPESRC programming is also being updated (as Panel fitter input), then the 'fb' already attached to 'crtc' may not be aligned with it. So there could be a momentary corruption caused when internal modeset is done by Driver (to change the Panel fitter setting), which will last till the next page flip (or setplane).
> 
> 
> > No, we need both the border and the PIPESRC information. hdisplay/vdisplays isn't enough since the user facing mode structure doesn't have vblank_start/end fields. Hence we can't specify borders.
> > If we don't want to extend the display mode, we should add border properties of some sort. I know some drivers have added something like that to the connectors, but again since the mode is applied to the crtc, ideally these properties
> > should also be on the crtc.
> 
> Sorry but it's not quite clear. This is what is my understanding so far, please kindly correct wherever wrong.
> 
> 1.   We need border info for the output of Panel fitter, which will determine the display window. Using the border info we will manipulate the hblank/vblank start/end fields.
> 2.   Currently the values of 'hdisplay/vdisplay' fields sent in 'drm_mode_modeinfo' structure gets programmed in PIPESRC. So if we are adding border info to the same structure, then we can use the 'hdisplay/vdisplay' fields only for   
>       PIPESRC. But if we are defining a new property, to convey the border info, then we need the PIPESRC information also along with it.
> 
> Please confirm that should we add a new a 'blob' type property for 'crtc' ? 

In my ideal solution the panel fitter output will be hdisplay/vdisplay
+/- the border (depending on which way we define it), and the panel fitter
input size will be defined as a new crtc property.

-- 
Ville Syrjälä
Intel OTC