Re: [PATCH 08/21 v2] drm/i915: Add helper function to update scaler_users in crtc_state

Konduru, Chandra
2015-03-25T22:02:12Z

> -----Original Message-----
> From: Roper, Matthew D
> Sent: Wednesday, March 25, 2015 1:59 PM
> To: Konduru, Chandra
> Cc: intel-gfx@lists.freedesktop.org; Vetter, Daniel; Conselvan De Oliveira, Ander
> Subject: Re: [PATCH 08/21 v2] drm/i915: Add helper function to update
> scaler_users in crtc_state
>
> On Wed, Mar 25, 2015 at 12:20:08PM -0700, Konduru, Chandra wrote:
> ...
> > >
> > > We're already calculating this in the plane check function; we
> > > should probably just store the result in a plane_state field at that
> > > point so we don't have to re- calculate it here.
> >
> > I think you are referring to sprite plane check, but this is not there
> > in primary plane check function.
>
> Well, it is, but it's hidden inside the drm plane helper function and isn't directly in
> our i915 driver code.
>
> I feel like "do these src/dest rectangles imply scaling?" is a question that is going
> to be relevant to all drivers, not just i915, so it might even be worth adding the
> field to the DRM core's state structure and have the helper function set it for any
> drivers using the helper.
> Hardware drivers could override this value, or could set it themselves if they
> don't use the helper. Just a thought...

I think that makes sense, but not planning in this patch series.

>
>
> Matt
>
> --
> Matt Roper
> Graphics Software Engineer
> IoTG Platform Enabling & Development
> Intel Corporation
> (916) 356-2795