Re: [Intel-gfx] [PATCH 0/8] Enable eDP PSR functionality at HSW - v3

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

On Thu, Feb 28, 2013 at 02:52:32PM -0300, Paulo Zanoni wrote:
> Hi
> 
> 2013/2/25 Rodrigo Vivi <rodrigo.vivi@gmail.com>:
> > PSR is an eDP feature that allows power saving even with static image at eDP screen.
> >
> > v3: Accepted many suggestions that I received at v2 review, fixing, cleaning and improving the code.
> >
> > v2: Main differences in this v2:
> > - Created vbt struct to get i915 dev_priv more organized and to avoid adding more stuff into it.
> > - migrated hsw macros to use transcoder instead of pipes than I could address eDP
> > - remove patch that was only adding edp psr registers and added them on demand
> >
> > v1:
> > Shobit Kumar has implemented this patch series some time ago, but had no eDP panel with PSR capability to test them.
> >
> > I could test and verify that this series fully identify PSR capability and enables it at HSW.
> > I also verified that it saves from 0.5-1W but only when in blank screen. It seems it is not really entering in sleeping mode with static image at eDP screen yet.
> 
> What do you mean with "blank screen"? It seems we disable PSR before
> blanking the screen, so the 0.5-1W saving could be from the backlight.
> Did you try masking more bits on the SRD_DEBUG register to see if it
> enters PSR more easily? The first test I'd try would be to set 1 to
> all those mask regs and see what happens (maybe we'll enter PSR and
> never ever leave it again?).

One thing I'm wondering if we can even enable PSR w/o implementing the
FBC tracking bits. I mean what happens if someone renders to the front
buffer while PSR is active?

-- 
Ville Syrjälä
Intel OTC