Re: [PATCH v2 0/8] eDP DRRS based on frontbuffer tracking

Daniel Vetter
2014-12-18T20:15:11Z

On Thu, Dec 18, 2014 at 09:02:14PM +0530, Vandana Kannan wrote:
> This patch series inserts DRRS into frontbuffer tracking mechanism.
>
> 1. Previous submission for this feature was designed considering only eDP
> DRRS. In this series, apart from following fb tracking, changes have been made
> to make structures generic so that it can be of use to any other code
> addition to support DRRS with other display types.
> 2. DRRS support is checked based on VBT setting and panel's capability (if
> more than one RR is supported).
> 3. Based on DRRS support availability, related structures are initialized or
> cleaned up through calls from enable/disable DDI respectively.
> 4. Since flip() indicates busyness, changes have been made to invalidate
> DRRS during flip. This changes RR back to preferred mode RR. New work to set
> low RR is scheduled after a delay of 1 second.
> 5. This series includes patches to support RR switching on all platforms.
>
> v2: As discussed with Daniel, discarding the patch which added a module
> param to specify the delay before entering DRRS. This delay has been fixed
> to 1 second.
> The call to invalidate DRRS from page_flip still remains - will be
> changed (or kept as is) depending on the behavior on Android..
> Right now testing is done using vbltest in libdrm.. But i-g-t for DRRS is WIP.

Really please remove these two hunks in the pageflip code because:
- the frontbuffer tracking code _does_ flush on flips
- you're just moving moving the call around in the same function, that
doesn't have any effect.

Or maybe I'm blind, but then you need to explain what exactly changes in
perceived behaviour.

Thanks, Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch