885620 - Support FB fallback when HWC isn't available

Status: RESOLVED FIXED

(Core Graveyard :: Widget: Gonk, defect)

Description

[Michael Wu [:mwu]]

Attachment: Add framebuffer drawing path

The emulator doesn't support HWC. This provides an alternate path so we can draw in the emulator.

Comment 1

[Michael Wu [:mwu]]

Comment on attachment 765747 [details] [diff] [review]
Add framebuffer drawing path

Review of attachment 765747 [details] [diff] [review]:
-----------------------------------------------------------------

::: widget/gonk/libdisplay/GonkDisplayJB.cpp
@@ +46,5 @@
> +    if (!err) {
> +        mWidth = mFBDevice->width;
> +        mHeight = mFBDevice->height;
> +        xdpi = mFBDevice->xdpi;
> +        surfaceformat = HAL_PIXEL_FORMAT_RGBX_8888;

I had to use RGBX here instead of the format reported by the framebuffer, which is RGBA8888. EGL fails to return any configurations with RGBA. I'll add a comment.

Comment 2

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

Comment on attachment 765747 [details] [diff] [review]
Add framebuffer drawing path

Does it hurt to open to FB device always?  RGBX thing makes sense (but weird, FB device really should be reporting RGBX!), comment is good.

Comment 3

[Michael Wu [:mwu]]

(In reply to Vladimir Vukicevic [:vlad] [:vladv] from comment #2)
> Comment on attachment 765747 [details] [diff] [review]
> Add framebuffer drawing path
> 
> Does it hurt to open to FB device always?  RGBX thing makes sense (but
> weird, FB device really should be reporting RGBX!), comment is good.

Surfaceflinger actually always tries to open the FB device first in order to be more compatible with older HALs, so this actually helps in theory.

Comment 4

[Michael Wu [:mwu]]

https://hg.mozilla.org/projects/birch/rev/6ab7e5820bb9

.. And I just realized I completely forgot to add the comment. Will add in a follow up..

Comment 5

[Michael Wu [:mwu]]

https://hg.mozilla.org/projects/birch/rev/d86e7ee8f564

Comment 6

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/6ab7e5820bb9
https://hg.mozilla.org/mozilla-central/rev/d86e7ee8f564