1138811 - (RefactorHwc) [META] Refactor HwcComposer2D

Status: RESOLVED INVALID

(Core Graveyard :: Widget: Gonk, defect)

Description

[Boris Chiou [:boris]]

There are many hard codes and definitions for different Android versions in HwcComposer2D, and we want to add the OverlayImage layer into HwcComposer2D in the future. I think it's a good chance to refactor HwcComposer2D for different version and platforms(ex. qcom, mtk).

Comment 1

[Michael Wu [:mwu]]

We need to support one interface per Android version and avoid vendor specific forks within the tree. Platform specific modifications should not be encouraged.

Comment 2

[Peter Chang[:pchang]]

(In reply to Michael Wu [:mwu] from comment #1)
> We need to support one interface per Android version and avoid vendor
> specific forks within the tree. Platform specific modifications should not
> be encouraged.

Agree, we should avoid the platform specific modifications in single android version.
Let's separate HwcComposer2D by version first and see how many hw specific changes.

Comment 3

[Peter Chang[:pchang]]

There is another thought that could be considered in this refactor.
If we treat HWC HAL as a separate module, and call them as hal.set()/hal.commit(), it is possible to create the mockhal to verify the layer lists input are valid or not. For example, we can run this mockhal in GIT and then we can verify latest gaia/gecko are HWC friendly or not. But we may have trouble to check the graphic buffer existed or not for every layer during the validation.

Comment 4

[Michael Wu [:mwu]]

If you want to, I think splitting ICS away from JB/KK/L support might make sense. In general, I would like to avoid splitting implementations for different versions into different files unless they're *very* different.

Comment 5

[Boris Chiou [:boris]]

Current plan:
1. Bug 1144012: Wrap HwcDevcie from HwcComposer2D
    - Purpose: Remove most version definitions and wrap them
    - Create HwcHALBase/HwcHAL/HwcICS classes
    - Wrap HwcDevice
2. Bug 1159592: Refine preparing layer list and wrap HwcList from HwcComposer2D
    - Purpose: Make PrepareLayerList more readable and handle different layers easier
    - Wrap HwcList (refine HwcLayer memory relocation)
    - Wrap the filling of layer info (for different versions and overlay image layer info)
3. Bug 1159597 Refine partial composition code in HwcComposer2D
    - Purpose: Refine different composition paths and make it more readable
    - Revise TryHwComposition (and/or Render)
    - Make it easier to add a new composition type (ex. HWC_OVELAYIMAGE)

After finishing these bugs, we can start to handle Bug 1149296 (Support OverlayImage Layer)

Comment 6

[Boris Chiou [:boris]]

Attachment: Discussion about refactoring HwcComposer2D