mmal_port_disable() hangs up

[vzhukovskyy]

Closing decoder-encoder connection hangs up in mmal_port_disable(). On 2 raspberries it constantly works fine, on 2 always hangs up.

#0  0x76efa088 in futex_abstimed_wait_cancelable (private=0, abstime=0x0, expected=1, futex_word=0x768e51a8 <client+36>) at ../sysdeps/unix/sysv/linux/futex-internal.h:205
#1  do_futex_wait (sem=sem@entry=0x768e51a8 <client+36>, abstime=0x0) at sem_waitcommon.c:115
#2  0x76efa1f4 in __new_sem_wait_slow (sem=0x768e51a8 <client+36>, abstime=0x0) at sem_waitcommon.c:282
#3  0x768cf9c0 in mmal_vc_sendwait_message () from /opt/vc/lib/libmmal_vc_client.so
#4  0x768d2854 in mmal_vc_port_disable () from /opt/vc/lib/libmmal_vc_client.so
#5  0x76d977d8 in mmal_port_disable_internal () from /opt/vc/lib/libmmal_core.so
#6  0x76d983d8 in mmal_port_disable () from /opt/vc/lib/libmmal_core.so
#7  0x00014fd0 in video_transcode (arg=0x0) at video_transcode.c:236
#8  0x76ef0494 in start_thread (arg=0x683fa440) at pthread_create.c:486
#9  0x76b21578 in ?? () at ../sysdeps/unix/sysv/linux/arm/clone.S:73 from /lib/arm-linux-gnueabihf/libc.so.6

I close the connection like this:

    MMAL_CHECK(mmal_port_disable(decoder->input[0]));
    MMAL_CHECK(mmal_port_disable(encoder->output[0]));
    mmal_port_pool_destroy(decoder->input[0], decoder_pool_in);
    mmal_port_pool_destroy(encoder->output[0], encoder_pool_out);
    MMAL_CHECK(mmal_connection_disable(conn));
    MMAL_CHECK(mmal_connection_destroy(conn));
    MMAL_CHECK(mmal_component_destroy(decoder));
    MMAL_CHECK(mmal_component_destroy(encoder));

This code works OK on

PI3 1.2GHz

cat /etc/rpi-issue
Raspberry Pi reference 2020-02-13
vcgencmd version
Feb 12 2020 12:38:08 
uname -a
Linux r3 4.19.97-v7+ #1294 SMP Thu Jan 30 13:15:58 GMT 2020 armv7l GNU/Linux

PI3 1.2GHz

cat /etc/rpi-issue
Raspberry Pi reference 2019-09-26
vcgencmd version
Sep 24 2019 17:37:19
uname -a
Linux r4 4.19.75-v7+ #1270 SMP Tue Sep 24 18:45:11 BST 2019 armv7l GNU/Linux

Does not work on

PI3 1.4GHz

cat /etc/rpi-issue
Raspberry Pi reference 2021-01-11
vcgencmd version
Jan  8 2021 14:33:35
uname -a
Linux r2 5.4.83-v7+ #1379 SMP Mon Dec 14 13:08:57 GMT 2020 armv7l GNU/Linux  

PI4

cat /etc/rpi-issue
Raspberry Pi reference 2020-05-27
vcgencmd version
Jan 27 2021 22:20:57
uname -a
Linux r5 5.10.11-v7l+ #1399 SMP Thu Jan 28 12:09:48 GMT 2021 armv7l GNU/Linux

The reason why I explicitly destroy pools is that my program starts and stops encoding periodically, and if I don't destroy pools, vc.ril.video_de and vc.ril.video_en threads do not exit and stack up, in mmal logs there is a "delayed destruction" message because of unreleased reference.

Before disabling the ports I send EOS and wait until I receive it back, if it matters.

The only line that appears in the logs enabled with export VC_LOGLEVEL=mmal:trace is this mmal: mmal_port_disable: vc.ril.video_decode(2:0) port 0x67a00ea0