[Gta04-owner] Fighting DRM

[Josua Mayer]

Greetings once again,

I have made some progress with drm_hwcomposer and finally debugged a
crazy crash in surfaceflinger. The crash is related to a DRM connector
that probably does not exist in kernel for the main display of the gta04.

So lets start with a log, and some inline comments:
01-01 09:11:24.354  2122  2122 I SurfaceFlinger: SurfaceFlinger is starting
01-01 09:11:24.359  2122  2122 I SurfaceFlinger: SurfaceFlinger's main
thread ready to run. Initializing graphics H/W...
01-01 09:11:24.379  2122  2122 D libEGL  : Emulator without GPU support
detected. Fallback to software renderer.
01-01 09:11:24.449  2122  2122 D libEGL  : loaded
/system/lib/egl/libGLES_android.so
01-01 09:11:24.680  2122  2122 E gralloc : failed to put fb info
This is harmless, gralloc tried to set the framebuffer to 480x1280 to
allow for flipping, and failed.

01-01 09:11:24.682  2122  2122 W gralloc : page flipping not supported
(yres_virtual=640, requested=1280)
01-01 09:11:24.683  2122  2122 I gralloc : using (fd=12)
01-01 09:11:24.683  2122  2122 I gralloc : id           = omapdrm
01-01 09:11:24.683  2122  2122 I gralloc : xres         = 480 px
01-01 09:11:24.683  2122  2122 I gralloc : yres         = 640 px
01-01 09:11:24.683  2122  2122 I gralloc : xres_virtual = 480 px
01-01 09:11:24.683  2122  2122 I gralloc : yres_virtual = 640 px
01-01 09:11:24.683  2122  2122 I gralloc : bpp          = 32
01-01 09:11:24.683  2122  2122 I gralloc : r            = 16:8
01-01 09:11:24.683  2122  2122 I gralloc : g            =  8:8
01-01 09:11:24.683  2122  2122 I gralloc : b            =  0:8
01-01 09:11:24.683  2122  2122 I gralloc : width        = 76 mm
(160.421051 dpi)
01-01 09:11:24.683  2122  2122 I gralloc : height       = 102 mm
(159.372543 dpi)
01-01 09:11:24.683  2122  2122 I gralloc : refresh rate = 60.00 Hz
01-01 09:11:24.899  2122  2122 E hwc-drm-plane: Could not get rotation
property
01-01 09:11:24.910  2122  2122 I hwc-drm-plane: Could not get alpha property
01-01 09:11:25.021  2122  2122 E hwc-drm-plane: Could not get rotation
property
01-01 09:11:25.030  2122  2122 I hwc-drm-plane: Could not get alpha property
01-01 09:11:25.152  2122  2122 E hwc-drm-plane: Could not get rotation
property
01-01 09:11:25.160  2122  2122 I hwc-drm-plane: Could not get alpha property
these are harmless too, no rotation or alpha are assumed.

01-01 09:11:25.207  2122  2140 E cutils-trace: Error opening trace file:
Permission denied (13)
01-01 09:11:25.207  2122  2140 W hwc-gl-worker:
EGL_ANDROID_native_fence_sync extension not supported
01-01 09:11:25.207  2122  2140 E libEGL  : eglMakeCurrent:813 error 3009
(EGL_BAD_MATCH)
01-01 09:11:25.207  2122  2140 E hwc-gl-worker: Failed to make the
OpenGL ES Context current: EGL_BAD_MATCH
01-01 09:11:25.207  2122  2140 E hwc-drm-display-compositor: Failed to
initialize OpenGL compositor 1
01-01 09:11:25.207  2122  2140 E hwc-drm-compositor-worker: Failed to
composite! 1
01-01 09:11:25.212  2122  2142 W hwc-gl-worker:
EGL_ANDROID_native_fence_sync extension not supported
01-01 09:11:25.212  2122  2142 E libEGL  : eglMakeCurrent:813 error 3009
(EGL_BAD_MATCH)
01-01 09:11:25.212  2122  2142 E hwc-gl-worker: Failed to make the
OpenGL ES Context current: EGL_BAD_MATCH
01-01 09:11:25.212  2122  2142 E hwc-drm-display-compositor: Failed to
initialize OpenGL compositor 1
01-01 09:11:25.212  2122  2142 E hwc-drm-compositor-worker: Failed to
composite! 1
01-01 09:11:25.214  2122  2122 I SurfaceFlinger: Using composer version 1.4
01-01 09:11:25.215  2122  2122 E hwcomposer-drm: Failed to get connector
for display 0
Does this hint at a problem?

01-01 09:11:25.216  2122  2122 E SurfaceFlinger: queryDisplayProperties:
Invalid display config! -1
This may be another one

01-01 09:11:25.219  2122  2122 W SurfaceFlinger: no suitable EGLConfig
found, trying a simpler query
01-01 09:11:25.229  2122  2122 W SurfaceFlinger: EGL_SLOW_CONFIG selected!
01-01 09:11:25.239  2122  2122 I SurfaceFlinger: EGL information:
01-01 09:11:25.239  2122  2122 I SurfaceFlinger: vendor    : Android
01-01 09:11:25.240  2122  2122 I SurfaceFlinger: version   : 1.4 Android
META-EGL
01-01 09:11:25.240  2122  2122 I SurfaceFlinger: extensions:
EGL_KHR_get_all_proc_addresses EGL_ANDROID_presentation_time
EGL_KHR_swap_buffers_with_damage EGL_KHR_image_base EGL_KHR_fence_sync
EGL_ANDROID_image_native_buffer
01-01 09:11:25.249  2122  2122 I SurfaceFlinger: Client API: OpenGL_ES
01-01 09:11:25.249  2122  2122 I SurfaceFlinger: EGLSurface: 8-8-8-8,
config=0x4
01-01 09:11:25.252  2122  2122 I SurfaceFlinger: OpenGL ES informations:
01-01 09:11:25.252  2122  2122 I SurfaceFlinger: vendor    : Android
01-01 09:11:25.253  2122  2122 I SurfaceFlinger: renderer  : Android
PixelFlinger 1.4
01-01 09:11:25.253  2122  2122 I SurfaceFlinger: version   : OpenGL
ES-CM 1.0
01-01 09:11:25.254  2122  2122 I SurfaceFlinger: extensions:
GL_EXT_debug_marker GL_OES_byte_coordinates GL_OES_fixed_point
GL_OES_single_precision GL_OES_read_format
GL_OES_compressed_paletted_texture GL_OES_draw_texture GL_OES_matrix_get
GL_OES_query_matrix GL_OES_EGL_image GL_OES_EGL_sync
GL_OES_compressed_ETC1_RGB8_texture GL_ARB_texture_compression
GL_ARB_texture_non_power_of_two GL_ANDROID_user_clip_plane
GL_ANDROID_vertex_buffer_object GL_ANDROID_generate_mipmap
01-01 09:11:25.254  2122  2122 I SurfaceFlinger: GL_MAX_TEXTURE_SIZE = 4096
01-01 09:11:25.254  2122  2122 I SurfaceFlinger: GL_MAX_VIEWPORT_DIMS = 4096
01-01 09:11:25.255  2122  2122 I SurfaceFlinger: Going to initialize
connected, and primary displays.
01-01 09:11:25.255  2122  2122 I SurfaceFlinger: Initializing connected
or primary display 0.
I inserted these two log messages in SurfaceFlinger.cpp:init(), and then
many markers (redacted in this log)
01-01 09:11:25.268  2122  2122 I SurfaceFlinger: MARKER 202
And this is the last thing that happens before the crash. This marker is
in HWComposer.cpp: getWidth(). The only thing that can go wrong here is
accessing a pointer at index currentConfig, which is initialized to 0,
and it does :(
The call stack as follows:
SurfaceFlinger.cpp: new FramebufferSurface(*mHwc, i, consumer);
FramebufferSurface.cpp:
mConsumer->setDefaultBufferSize(mHwc.getWidth(disp),  mHwc.getHeight(disp));
HWComposer.cpp: return mDisplayData[disp].configs[currentConfig].width;

01-01 09:11:25.275  2122  2122 F libc    : Fatal signal 11 (SIGSEGV),
code 1, fault addr 0x0 in tid 2122 (surfaceflinger)


So HWComposer assumes that mDisplayData[disp].configs exists and has at
least 1 entry. But for some reason, in this very case it is a
null-pointer. How can this be? The list of configurations is filled in
HWComposer.cpp: queryDisplayProperties.
We have already received a hint that something might have gone wrong,
however there is still a chance to find a configuration now by asking
the drm_hwcomposer with a call to mHwc->getDisplayAttributes. This call
is done in a for loop, but *only* if we get past a call to
mHwc->getDisplayConfigs.
This one translates to hwc_get_display_configs in drm_hwcomposer>
hwcomposer.cpp.
And there we find a familiar message in the code:
ALOGE("Failed to get connector for display %d", display);

So, we found the culprit! For some reason
ctx->drm.GetConnectorForDisplay(display) has failed.
Why? Well, I'd think the answer is in the DRM subsystem of the kernel. I
did a little googling, but couldn't come to any conclusions.
The only related thing I noticed is that every connector has a type, but
it is Unknown for dispc displays in omapdss.
However I was not able to confirm if that would prevent it from being
returned as a connector.
Or maybe there just is no such thing called a connector in this setup?

Anyhow this is where I can't continue.

Nikolaus, you hinted that some xorg drivers have problems too. With a
little luck the modesetting driver is one of those, and just maybe it
suffers from teh same issue? I think this is worth investigating at some
point.
I will now see if I can hack the hwcomposer library to grab display
properties from the framebuffer device instead. There is already code to
do that, but ggated by an if-clause to prefer calls to drm_hwcomposer.

br
Josua Mayer