Re: [PATCH v2 02/14] v4l: vsp1: Don't recycle active list at display start

[Mauro Carvalho Chehab <mchehab@s-opensource.com>]

Em Thu, 13 Jul 2017 18:02:20 +0100
Kieran Bingham <kieran.bingham@ideasonboard.com> escreveu:

> Hi Laurent,
> 
> On 26/06/17 19:12, Laurent Pinchart wrote:
> > When the display start interrupt occurs, we know that the hardware has
> > finished loading the active display list. The driver then proceeds to
> > recycle the list, assuming it won't be needed anymore.
> > 
> > This assumption holds true for headerless display lists, as the VSP
> > doesn't reload the list for the next frame if it hasn't changed.
> > However, this isn't true anymore for header display lists, as they are
> > loaded at every frame start regardless of whether they have been
> > updated.
> > 
> > To prepare for header display lists usage in display pipelines, we need
> > to postpone recycling the list until it gets replaced by a new one
> > through a page flip. The driver already does so in the frame end
> > interrupt handler, so all we need is to skip list recycling in the
> > display start interrupt handler.
> > 
> > While the active list can be recycled at display start for headerless
> > display lists, there's no real harm in postponing that to the frame end
> > interrupt handler in all cases. This simplifies interrupt handling as we
> > don't need to process the display start interrupt anymore.
> > 
> > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>  
> 
> Ok, I had skipped this one as I was concerned about its effects in relation to
> 11/14 but I see how that's working now.
> 
> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Acked-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Thanks,
Mauro