Libreelec 8&9 Kernel regression (VAAPI)

Mettbrot · February 22, 2017 at 6:01 PM

Hello,

I have been experiencing a problem for some time now: Kodi freezes when I watch SD content with VAAPI enabled. I posted about it here and we hunted it down to beeing a kernel bug.
It does not happen on Ubuntu 16.04.1 LTS, it does not happen on a downgraded kernel version of Libreelec (the one posted on the TRAC ticket by fritsch).

LE 9 Debug Log: DiPD dmesg: LHCL

LE 8.1.1 Debug Log: OWYL

LE 8 Debug log: UIQO
Debug log Kodi beta3: WCDf
dmesg after the freeze: HdUP
gdb debug: MNhA
File to reproduce: Die Ruhrpottwache-SAT.12017-02-1712-59.ts?dl=1

Remark from fritsch:

Quote

From my first analysis it looks like something mesa intel driver vs. xserver vs. egl

Thank you for looking into this, let me know if I can help any further.

Mettbrot · February 28, 2017 at 3:37 PM

Can I try anything else?

Mettbrot · March 18, 2017 at 1:37 PM

Any news on this?

mraction · July 25, 2017 at 6:25 PM

Hi Mettbrot,

any news for that problem?

**lrusak** · July 25, 2017 at 8:07 PM Official Post

There won't be any fixes here for the Kodi krypton 17.x series. You are better off trying a development build with kodi 18 as lot's has changed with video player and vaapi

Mettbrot · September 13, 2017 at 1:09 PM

I just tried again with the most recent Milhouse Build of LE9 (

LibreELEC-Generic.x86_64-9.0-Milhouse-20170912210333-%230912-g191d228)

and it happens too.

Debug Log LE9: DiPD

dmesg: LHCL

Mettbrot · September 16, 2017 at 5:01 PM

I would really like to get to the bottom of this. If there is anything else I can test or provide let me know...

Mettbrot · September 29, 2017 at 9:14 AM

mraction If you have the same problem, maybe you could also test with the video file I provided and a clean install (or "live" boot) of Libreelec. Post a debug log and maybe we can get this thing worked out

**milhouse** · October 5, 2017 at 7:11 PM

I tested my latest build, #1004 (based on kernel 4.13.4) with your test file streamed over smb:// and didn't have a problem while using a NUC6i5SYH.

Can you try disabling MPEG-2 VAAPI hardware acceleration as below, and see if that helps you?

I have MPEG-2 VAAPI enabled, and it works fine - no freeze - but there's obviously a problem with your system/configuration so this might allow you to work around it.

Looking at your dmesg, LHCL, there's a GPU hang being reported. Unfortunately that could be anything - a kernel bug, or (more likely) an Intel driver bug.

If you wish to raise a bug, please follow the guidelines here, in section "1.1 DRM Kernel" - add "drm.debug=0x1e log_buf_len=2M" on your kernel command line, reproduce the bug, then open a bug report and attach all of the files documented in the "DRM Kernel" section.

Mettbrot · October 6, 2017 at 11:02 AM

Thank you for your answer!

I can workaround the bug by disabling MPEG-2 VAAPI. Thats what I have to do since the last couple of versions

If I remember correctly I tried with the build fritsch provided in the kodi trac and it worked with this one. Wouldn't this one hang too if it was a driver issue?

How do I adapt the kernel command line? Is this something I can do at boot? Can it be done in a live environment? I like to boot "live" to have the stock image for testing.

Can I append them like this in syslinux.cfg?

Code

LABEL live
  KERNEL /KERNEL
  APPEND boot=UUID=3108-2154 live quiet tty vga=current drm.debug=0x1e log_buf_len=2M

just tried this, at least they show up in proc/cmdline so I guess thats fine. Running the test now..

Mettbrot · October 6, 2017 at 1:15 PM

OK, I think I got it. I had to restart the video ~20 times before it happened. Maybe you could confirm its a driver bug before I file it with them?

Kodi.log: RfDH

dmesg: eYSc

Unfortunately, its only the last part of the dmesg, I guess the buffer was too small for that.

Code

LibreELEC:~ # uname -m
x86_64
LibreELEC:~ # uname -r
4.13.4
LibreELEC:~ # xrandr --verbose | paste
http://sprunge.us/effM
LibreELEC:~ # dmesg | paste
http://sprunge.us/eYSc
LibreELEC:~ # cat /sys/class/drm/card0/error | gzip > error.gz
LibreELEC:~ # echo 1 > /sys/devices/pci0000:00/0000:00:02.0/rom
LibreELEC:~ # cat /sys/devices/pci0000:00/0000:00:02.0/rom > vbios.dump
LibreELEC:~ # echo 0 > /sys/devices/pci0000:00/0000:00:02.0/rom

Display More

error.gz?dl=1

vbios.dump?dl=1

Mettbrot · October 10, 2017 at 10:43 AM

Here it goes: 103185 – Intel GPU hang