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?