A mpd_oled is crashing in idle/clock mode after switching to 64bit.

[kan-ibal]

I have upgraded my rAudio based on Arch from 32bit to 64bit and cannot make mpd_oled to work while in idle/clock mode. During a playback mpd_oled is working ok.

systemctl status mpd_oled 

mpd_oled.service - MPD OLED Display
     Loaded: loaded (/etc/systemd/system/mpd_oled.service; disabled; preset: disabled)
     Active: failed (Result: core-dump) since Tue 2023-08-15 12:37:21 CEST; 3s ago
   Duration: 1min 32.529s
    Process: 4662 ExecStart=/usr/local/bin/mpd_oled -a 3c -o 3 -b 10 -g 1
   Main PID: 4662 (code=dumped, signal=ABRT)
        CPU: 32.550s

Aug 15 12:35:47 rAudio systemd[1]: Started MPD OLED Display.
Aug 15 12:37:20 rAudio systemd[1]: Stopping MPD OLED Display...
Aug 15 12:37:21 rAudio systemd[1]: mpd_oled.service: Main process exited, code=dumped, status=6/ABRT
Aug 15 12:37:21 rAudio systemd[1]: mpd_oled.service: Failed with result 'core-dump'.
Aug 15 12:37:21 rAudio systemd[1]: Stopped MPD OLED Display.
Aug 15 12:37:21 rAudio systemd[1]: mpd_oled.service: Consumed 32.550s CPU time.

and

journalctl -r

Aug 15 12:37:21 rAudio systemd[1]: [email protected]: Deactivated successfully.
Aug 15 12:37:21 rAudio systemd[1]: mpd_oled.service: Consumed 32.550s CPU time.
Aug 15 12:37:21 rAudio systemd[1]: Stopped MPD OLED Display.
Aug 15 12:37:21 rAudio systemd[1]: mpd_oled.service: Failed with result 'core-dump'.
Aug 15 12:37:21 rAudio systemd[1]: mpd_oled.service: Main process exited, code=dumped, status=6/ABRT
Aug 15 12:37:21 rAudio systemd-coredump[6492]: [LNK] Process 4662 (mpd_oled.new) of user 0 dumped core.
                                               
                                               Stack trace of thread 4662:
                                               #0  0x0000007f9eef2790 n/a (libc.so.6 + 0x82790)
                                               #1  0x0000007f9eeab6fc raise (libc.so.6 + 0x3b6fc)
                                               #2  0x0000007f9ee978b0 abort (libc.so.6 + 0x278b0)
                                               #3  0x000000559175b03c n/a (/usr/local/bin/mpd_oled + 0x2b03c)
                                               #4  0x000000559175b03c n/a (/usr/local/bin/mpd_oled + 0x2b03c)
                                               #5  0x0000007f9f1917ac n/a (linux-vdso.so.1 + 0x7ac)
                                               #6  0x0000007f9ef2484c clock_nanosleep (libc.so.6 + 0xb484c)
                                               #7  0x000000559187c648 n/a (/home/.local/bin/mpd_oled.new + 0x14c648)
                                               ELF object binary architecture: AARCH64
Aug 15 12:37:20 rAudio systemd[1]: Started Process Core Dump (PID 6487/UID 0).
Aug 15 12:37:20 rAudio systemctl[6481]: See system logs and 'systemctl status mpd_oled.service' for details.
Aug 15 12:37:20 rAudio systemctl[6481]: Failed to stop mpd_oled.service: Access denied
Aug 15 12:37:20 rAudio systemd[1]: Stopping MPD OLED Display...

I'm not sure it is a mpd_oled issue and for me it looks like mpd_oled is crashing because systemd is stopping its service.
But why? The same setup is working in 32bit system.

[antiprism]

Hi

Thanks for reporting the issue. Just to check, you have built a 64 bit mpd_oled binary from source on the sytem you are running the binary on. Were there any warnings printed when compiling? If you aren't sure, could you rebuild mpd_oled and review the output for any warnings or errors.

Adrian.

[kan-ibal]

Yes, I have built it on the same system I'm running the binary on. There were no warnings when compiling. I have to add that when I run binary in terminal from command line it works as it suppose to.

[antiprism]

The issue seems strange.

Just to confirm

• not playing music and running mpd_oled from the command line works fine, starting and stopping the music works fine
• playing music and running mpd_oled from the command line works fine, stopping and starting the music works fine
• not playing music and starting the mpd_oled service causes a crash
• playing music and starting the mpd_oled service does not cause a crash, stopping the music causes a crash

The backtrace contains the line

#7 0x000000559187c648 n/a (/home/.local/bin/mpd_oled.new + 0x14c648)

Do you know anything about "/home/.local/bin/mpd_oled.new"?

Could you post the contents of: /etc/systemd/system/mpd_oled.service

Adrian.

[kan-ibal]

• not playing music and running mpd_oled from the command line works fine, starting and stopping the music works fine

yes

• playing music and running mpd_oled from the command line works fine, stopping and starting the music works fine

yes (as above)

• not playing music and starting the mpd_oled service causes a crash
• playing music and starting the mpd_oled service does not cause a crash, stopping the music causes a crash

yes - stopping or pausing(mpc client)

The backtrace contains the line
#7 0x000000559187c648 n/a (/home/.local/bin/mpd_oled.new + 0x14c648)
Do you know anything about "/home/.local/bin/mpd_oled.new"?

Yes, my mistake. Should be as above, /usr/local/bin. That is from my other test attempt.

Could you post the contents of: /etc/systemd/system/mpd_oled.service

Now is:

[Unit]
Description=MPD OLED Display

[Service]
ExecStart=/usr/local/bin/mpd_oled -k -a 3c -o 3 -b 10 -g 1 -f 25 -c fifo,/tmp/mpd.fifo

[Install]
WantedBy=multi-user.target

[antiprism]

Hi

The service file isn't as expected, as it should start mpd_oled from a launch script that waits for mpd to start. I am not sure if it will help, but it would make sense to have the service file setup like a new install for testing. If you are not running the repository version of mpd_oled then please install that version instead. In all cases (even if you reinstall), reset the service file with

sudo mpd_oled_service_uninstall
sudo mpd_oled_service_install
sudo mpd_oled_service_edit -k -a 3c -o 3 -b 10 -g 1 -f 25 -c fifo,/tmp/mpd.fifo

List the contents of /etc/systemd/system/mpd_oled.service and check it is now running mpd_oled_launch instead of mpd_oled

Adrian.

[kan-ibal]

I don't think it will help as well. Yes, I admit that my service file is custom but for testing purposes I followed your path but mpd_oled_service_edit gives me:

rAudio:~/mpd_oled/scripts  #  ./mpd_oled_service_edit -k -a 3c -o 3 -b 10 -g 1 -f 25 -c fifo,/tmp/mpd.fifo
setting service file to run: mpd_oled '-k -a 3c -o 3 -b 10 -g 1 -f 25 -c fifo,/tmp/mpd.fifo'
sed: -e expression #1, char 79: unknown option to `s'

using manual setup:

[Unit]
Description=MPD OLED Display

[Service]
ExecStart=/usr/local/bin/mpd_oled_launch /usr/local/bin/mpd_oled -k -a 3c -o 3 -b 10 -g 1 -f 25 -c fifo,/tmp/mp
d.fifo -p mpd

[Install]
WantedBy=multi-user.target

doesn't change anything.

[antiprism]

Hi

I tracked down the sed error, and will fix it, thanks.

It is difficult to suggest more things to try, but maybe it is related to the system user that is used to run the mpd_oled program when the service starts it.

I'll see if I can install here and take a look. Where can I download the rAudio image are you using? Are there any other instructions to set up the system as you have done?

Adrian.

[kan-ibal]

Full image you can find here and update via rAudio GUI to the latest. There is no additional system setup I have that may be applicable for that mpd_oled issue.
For my display, in /boot/config.txt I have following settings:

dtparam=i2c_arm=on
dtparam=i2c_arm_baudrate=800000

and in /etc/modules-load.d/mpd_oled.conf
i2c-dev

How to set wi-fi you can find in readme.