[Mesa-dev] [PATCH 00/10] egl/android: Improve the Android EGL backend

[Rob Herring]

On Mon, Jul 18, 2016 at 11:29 PM, Tomasz Figa <tfiga at chromium.org> wrote:
> On Tue, Jul 19, 2016 at 12:35 PM, Rob Herring <robh at kernel.org> wrote:
>> On Fri, Jul 15, 2016 at 2:53 AM, Tomasz Figa <tfiga at chromium.org> wrote:
>>> Hi,
>>>
>>> This series is a collection of various fixes and extensions we came up
>>> with during our attempt to use Mesa for Android.
>>>
>>> Fixes included in this series:
>>>  - added mandatory EGL_MAX_PBUFFER_WIDTH and _HEIGHT attributes to EGL
>>>    configs,
>>>  - fixed multiple issues with handling pbuffers in the backend,
>>>  - found and fixed a DRI image leak,
>>>  - made the implementation of DRI image loader .getBuffers callback
>>>    conform better to the extension semantics.
>>>
>>> New features added by this series:
>>>  - possibility to build the Android EGL platform without drm_gralloc
>>>    headers,
>>>  - support for creating EGL images from Android native buffers with
>>>    YV12 pixel format (prime-only),
>>>  - fallback to kms_swrast driver when no hardware driver can be loaded
>>>    but there is still some usable DRI node present in the system.
>>>  - more logging in case of errors to help diagnosing problems.
>>>
>>> Testing was done using classic i965 (gen 8) and gallium softpipe drivers
>>> on an internal build of Android, based on gralloc backed by a DRM render
>>> node and sharing buffers by PRIME FDs.
>>
>> I've tested out patches 1-6 with virgl and I don't get anything
>> displayed. I get this message:
>>
>> EGL-DRI2: Front buffer is not supported for window surfaces
>>
>> That's as far as I investigated. I'll look into it some more tomorrow.
>
> Thanks a lot for testing!
>
> It looks like somehow your driver (or gallium) is triggering a call to
> DRI image loader getBuffers() callback with front buffer bit set in
> the image mask, but window surfaces on Android provide only back
> buffers.

I've debugged this a bit more, but still am not sure what's going on.
Reverting #6 fixes things though. I don't see how a specific driver
would cause the issue here. Here's the call stack for where the
warning is printed:

07-19 21:30:37.750  2153  2153 F DEBUG   :     #00 pc 000000000000fc8d
 /system/lib64/egl/libGLES_mesa.so (droid_image_get_buffers+77)
07-19 21:30:37.750  2153  2153 F DEBUG   :     #01 pc 0000000000319554
 /system/lib64/dri/gallium_dri.so (dri2_allocate_textures+660)
07-19 21:30:37.750  2153  2153 F DEBUG   :     #02 pc 00000000003157c6
 /system/lib64/dri/gallium_dri.so (dri_st_framebuffer_validate+566)
07-19 21:30:37.750  2153  2153 F DEBUG   :     #03 pc 00000000004eadf3
 /system/lib64/dri/gallium_dri.so (st_framebuffer_validate+115)
07-19 21:30:37.750  2153  2153 F DEBUG   :     #04 pc 00000000004ead4e
 /system/lib64/dri/gallium_dri.so
(st_manager_validate_framebuffers+78)
07-19 21:30:37.750  2153  2153 F DEBUG   :     #05 pc 00000000004c7450
 /system/lib64/dri/gallium_dri.so (st_validate_state+352)
07-19 21:30:37.750  2153  2153 F DEBUG   :     #06 pc 00000000004e6d5c
 /system/lib64/dri/gallium_dri.so (st_draw_vbo+172)
07-19 21:30:37.750  2153  2153 F DEBUG   :     #07 pc 00000000004acc31
 /system/lib64/dri/gallium_dri.so (vbo_draw_arrays+289)
07-19 21:30:37.750  2153  2153 F DEBUG   :     #08 pc 0000000000044dce
 /system/lib64/libsurfaceflinger.so
(android::GLES20RenderEngine::drawMesh(android::Mesh const&)+254)
07-19 21:30:37.750  2153  2153 F DEBUG   :     #09 pc 0000000000025af9
 /system/lib64/libsurfaceflinger.so
(android::Layer::drawWithOpenGL(android::sp<android::DisplayDevice
const> const&, android::Region const&, bool) const+329)

> My understanding of the semantics was that the callback should deny
> such requests, so that's how I implemented it. However it isn't really
> well documented, so potentially it should only provide buffers that
> are available and ignore the rest without bailing out. Could someone
> more familiar with this extension comment on this?
>
>>
>> Patches 7-10 wouldn't apply. Do you have a git tree with the series?
>
> Hmm, I rebased them on Mesa master just before sending. Let me try to
> create a sandbox branch in our chromium tree.

Turns out to be something in my tree...

Rob