Cannot run debug builds of ozone_demo

[EwanRoycroft]

Description

Debug builds of the ozone_demo target will exit after a few seconds, reporting Check failed: IsGpuFenceSupported().

More information

Attribute	Value
Version	86.0.4184.0 (32-bit)
Build	Debug
Platform	Ozone-GBM
Target	ozone_demo
Device	Raspberry Pi 4B (4GB)
OS	Raspbian 10 "buster"

Steps to reproduce

Make a debug build of ozone_demo for the Ozone-GBM platform and run on the RPi 4.

GN arguments

(Ignoring any additional codec args.)

use_ozone = true
ozone_platform_x11 = false
ozone_platform_gbm = true
ozone_platform_headless = false
use_vc4_minigbm = true

ffmpeg_branding = "Chrome"
proprietary_codecs = true

target_os="chromeos"
target_cpu = "arm"
use_sysroot = true
target_sysroot = "//build/linux/debian_sid_arm-sysroot"

enable_nacl = false
blink_symbol_level = 0

Command

EGL_PLATFORM=surfaceless ./ozone_demo --ozone-platform=gbm

Terminal output

sd-device-enumerator: Scan all dirs
sd-device-enumerator: Scanning /sys/bus
sd-device-enumerator: Scanning /sys/class
[0701/151429.935634:WARNING:gbm_surface_factory.cc(115)] Platform device extensions not found.
[0701/151433.625864:ERROR:drm_thread_proxy.cc(44)] Unable to initialize GBM for /sys/devices/platform/v3dbus/fec00000.v3d/drm/card0: Permission denied (13)
[0701/151433.894951:WARNING:screen_manager.cc(113)] Display controller (crtc=49) already present.
[0701/151433.908966:WARNING:drm_device_manager.cc(97)] Attempting to get device for unknown widget 1
sd-device-enumerator: Scan all dirs
sd-device-enumerator: Scanning /sys/bus
sd-device-enumerator: Scanning /sys/class
[0701/151434.232470:FATAL:gl_fence.cc(123)] Check failed: IsGpuFenceSupported().
#0 0x0000b6a84aa8 base::debug::CollectStackTrace()
#1 0x0000b691d0aa base::debug::StackTrace::StackTrace()
#2 0x0000b691d082 base::debug::StackTrace::StackTrace()
#3 0x0000b694392c logging::LogMessage::~LogMessage()
#4 0x0000b6943f12 logging::LogMessage::~LogMessage()
#5 0x0000b68fb82c logging::CheckError::~CheckError()
#6 0x0000b6e35836 gl::GLFence::CreateForGpuFence()
#7 0x0000004ffa2a ui::SurfacelessGlRenderer::RenderFrame()
#8 0x000000502490 base::internal::FunctorTraits<>::Invoke<>()
#9 0x000000502436 base::internal::InvokeHelper<>::MakeItSo<>()
#10 0x0000005023e4 _ZN4base8internal7InvokerINS0_9BindStateIMN2ui21SurfacelessGlRendererEFvvEJNS_7WeakPtrIS4_EEEEEFvvEE7RunImplIS6_NSt4__Cr5tupleIJS8_EEEJLj0EEEEvOT_OT0_NSD_16integer_sequenceIjJXspT1_EEEE
#11 0x0000005023b4 base::internal::Invoker<>::RunOnce()
#12 0x0000b68f5cb2 _ZNO4base12OnceCallbackIFvvEE3RunEv
#13 0x0000b69f37fe base::TaskAnnotator::RunTask()
#14 0x0000b6a1c77c base::sequence_manager::internal::ThreadControllerWithMessagePumpImpl::DoWorkImpl()
#15 0x0000b6a1c2f2 base::sequence_manager::internal::ThreadControllerWithMessagePumpImpl::DoWork()
#16 0x0000b6a1c9be base::sequence_manager::internal::ThreadControllerWithMessagePumpImpl::DoWork()
#17 0x0000b6acddb0 base::MessagePumpLibevent::Run()
#18 0x0000b6a1cef6 base::sequence_manager::internal::ThreadControllerWithMessagePumpImpl::Run()
#19 0x0000b69b3d5a base::RunLoop::Run()
#20 0x0000004fb064 main
#21 0x0000b57cc718 __libc_start_main
Task trace:
#0 0x0000004ff4bf ui::SurfacelessGlRenderer::PostRenderFrameTask()
#1 0x0000b6ccbe09 ui::DrmDisplayHost::OnDisplayConfigured()
#2 0x0000b5589b95 mojo::SimpleWatcher::Context::Notify()
#3 0x0000b5589b95 mojo::SimpleWatcher::Context::Notify()
#4 0x0000b6cce92b ui::DrmDisplayHostManager::GpuHasUpdatedNativeDisplays()
Task trace buffer limit hit, update PendingTask::kTaskBacktraceLength to increase.
IPC message handler context: 0x40F364F3

Received signal 6
#0 0x0000b6a84aa8 base::debug::CollectStackTrace()
#1 0x0000b691d0aa base::debug::StackTrace::StackTrace()
#2 0x0000b691d082 base::debug::StackTrace::StackTrace()
#3 0x0000b6a84988 base::debug::(anonymous namespace)::StackDumpSignalHandler()
#4 0x0000b57e2130 (/lib/arm-linux-gnueabihf/libc-2.28.so+0x2d12f)
[end of stack trace]
Calling _exit(1). Core file will not be generated.

[EwanRoycroft]

Terminal log above says "permission denied" for /sys/devices/platform/v3dbus/fec00000.v3d/drm/card0, but sometimes the error is different:

[0701/154026.193408:ERROR:drm_thread_proxy.cc(44)] Unable to initialize GBM for /sys/devices/platform/v3dbus/fec00000.v3d/drm/card0: No such file or directory (2)

Even though the directory exists:

pi@ewanrpi4:~ $ ll /sys/devices/platform/v3dbus/fec00000.v3d/drm/card0
total 0
-r--r--r-- 1 root root 4096 Jul  1 15:45 dev
lrwxrwxrwx 1 root root    0 Jul  1 15:45 device -> ../../../fec00000.v3d
drwxr-xr-x 2 root root    0 Jul  1 15:45 power
lrwxrwxrwx 1 root root    0 Jul  1 15:45 subsystem -> ../../../../../../class/drm
-rw-r--r-- 1 root root 4096 Jul  1 15:45 uevent

[EwanRoycroft]

Adding --disable-explicit-dma-fences fixes this.
https://dev.to/yaegashi/comment/13pif