953215 - Optimize per pixel alpha blending in H/W Composition.

Status: RESOLVED FIXED

(Firefox OS Graveyard :: General, defect, P2)

Description

[Sushil]

Attachment: Optimize per pixel alpha blending in H/W Composition.

Per pixel alpha blending operation is not needed when a layer is opaque and visible content on the layer is promised to be opaque. I have attached the corresponding patch.

Comment 1

[Sushil]

Please test it on ICS reference device with FFOS v1.3

Comment 2

[Sushil]

Tested on JB and ICS reference devices with FFOS v1.3. Please review.

Comment 3

[Diego Wilson [:diego]]

Comment on attachment 8351521 [details] [diff] [review]
Optimize per pixel alpha blending in H/W Composition.

Review of attachment 8351521 [details] [diff] [review]:
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LGTM

Comment 4

[Sushil]

Attachment: Optimize per pixel alpha blending in H/W Composition.

Uploading HG friendly version of reviewed patch.

Comment 5

[Jason Smith [:jsmith]]

Why was this nominated to block for 1.3?

Comment 6

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/integration/b2g-inbound/rev/16969ee4b04b

Comment 7

[Sushil]

(In reply to Jason Smith [:jsmith] from comment #5)
> Why was this nominated to block for 1.3?

Because it leads to MDP hang on b2g v1.3 device during monkey runs.

Setting default HWC_BLENDING_PREMULT on each layer leads to an unnecessary full-screen solid fill (clear with black color) in HAL on each frame during H/W composition which is unnecessary load on MDP. Plus it optimizes per pixel alpha blending operation.

Comment 8

[Sushil]

SurfaceFlinger in Android also follows same approach.

Comment 9

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/16969ee4b04b

Comment 10

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/30ab64d5e3f4