Bug Report No start on intel chipset

[Francois-Rene Rideau]

obs crashes at startup after last logging this line:
intel_do_flush_locked failed: Input/output error

Using obs-studio-20.1.0 from nixpkgs on Linux 4.13.9 x64 on a 2016 NUC where lspci says:
00:02.0 VGA compatible controller: Intel Corporation Iris Graphics 540 (rev 0a)

strace says the failing system call is:
ioctl(13, DRM_IOCTL_I915_GEM_EXECBUFFER2, 0x7fffd7e5c4c0) = -1 EIO (Input/output error)

I tried LIBGL_DRI3_DISABLE=1 obs or running as root with the same result. There is nothing in the syslog.

Full log:
Attempted path: share/obs/obs-studio/locale/en-US.ini
Attempted path: /nix/store/jw8dg8zij7v08pqnf1fsdsip0pyhk0xn-obs-studio-20.1.0/share/obs/obs-studio/locale/en-US.ini
Attempted path: share/obs/obs-studio/locale.ini
Attempted path: /nix/store/jw8dg8zij7v08pqnf1fsdsip0pyhk0xn-obs-studio-20.1.0/share/obs/obs-studio/locale.ini
Attempted path: share/obs/obs-studio/themes/Default.qss
Attempted path: /nix/store/jw8dg8zij7v08pqnf1fsdsip0pyhk0xn-obs-studio-20.1.0/share/obs/obs-studio/themes/Default.qss
Attempted path: share/obs/obs-studio/license/gplv2.txt
Attempted path: /nix/store/jw8dg8zij7v08pqnf1fsdsip0pyhk0xn-obs-studio-20.1.0/share/obs/obs-studio/license/gplv2.txt
info: CPU Name: Intel(R) Core(TM) i5-6260U CPU @ 1.80GHz
info: CPU Speed: 1800.000MHz
info: Physical Cores: 2, Logical Cores: 4
info: Physical Memory: 32069MB Total, 5597MB Free
info: Kernel Version: Linux 4.13.9
info: Distribution: NixOS "17.09.2075.ac35504065"
info: Portable mode: false
QMetaObject::connectSlotsByName: No matching signal for on_advAudioProps_clicked()
QMetaObject::connectSlotsByName: No matching signal for on_advAudioProps_destroyed()
info: OBS 0.0.1 (linux)
info: ---------------------------------
info: ---------------------------------
info: audio settings reset:
samples per sec: 44100
speakers: 2
info: ---------------------------------
info: Initializing OpenGL...
info: OpenGL version: 4.5 (Core Profile) Mesa 17.1.8
intel_do_flush_locked failed: Input/output error

 

[Francois-Rene Rideau]

Some pages suggested a kernel driver bug, so I rebooted under NixOS's older Linux 4.9.61, and obs started properly.

For the record, someone found a different workaround to a similar problem:
https://github.com/freeorion/freeorion/issues/1554