Great !! looks like the real fix (I'm going to rebuild my version of alsa-plugins with it and let you know).  Thanks  JP  23.10.2018, 09:37, "Jaroslav Kysela" <perex@xxxxxxxx>: Dne 23.10.2018 v 09:06 Hyperion napsal(a):  Sorry, I have no more time to spend debugging :(    Thus I guess that the true alsa maintainers will be much more efficient  than me (I'm just doing quick and dirty hacking here).    My XMOS USB soundcard now works with this workaround, please could you  take a look at traces I posted in the discussion on LQ.org ? Here is the better fix: [1]http://git.alsa-project.org/?p=alsa-plugins.git;a=commitdiff;h=a4 e7e1282c57a2f4e83afe9a4008042d8b4c5bb9 There was really a double pcm free, because:   snd_pcm_ioplug_delete ->     snd_pcm_close ->       snd_pcm_ioplug_close ->         a52_close() ->           snd_pcm_close(rec->slave)                                         Jaroslav     All the best  JP    23.10.2018, 08:53, "Jaroslav Kysela" <[2]perex@xxxxxxxx>:   Dne 23.10.2018 v 08:43 Hyperion napsal(a):          I have narrowed to the simpler patch below :          Â          Quote:          diff -rNaud alsa-plugins-1.1.7/a52/pcm_a52.c          alsa-plugins-1.1.7-new/a52/pcm_a52.c          --- alsa-plugins-1.1.7/a52/pcm_a52.c 2018-10-16 14:00:22.000000000          +0200          +++ alsa-plugins-1.1.7-new/a52/pcm_a52.c 2018-10-23      08:35:15.699830909          +0200          @@ -978,7 +978,8 @@          if ((err = a52_set_hw_constraint(rec)) < 0) {          snd_pcm_ioplug_delete(&rec->io);          - goto error;          + free(rec);          + return err;          }          *pcmp = rec->io.pcm;          Â  It does not appear like a correct change, because rec->slave is  initialized in previous lines (snd_pcm_open calls). Could you inspect  rec->slave in gdb ?                                                  Jaroslav              Â          22.10.2018, 23:30, "Hyperion" <[3]h1p8r10n@xxxxxxxxxx      <mailto:[4]h1p8r10n@xxxxxxxxxx>>:            Â   Hi,            Â   Â            Â   Since the upgrade to Alsa 1.1.7, I get a segfault at            pulseaudio            Â   startup. This have been discussed and documented here :            Â        [1][1][5]https://www.linuxquestions.org/questions/slackwar e-14/cu            rrent-fri-oc            Â   t-19-puseaudio-segfauts-4175640773/            Â   Â            Â   It seems that I found the origin of the bug :      reverting these            2 commits            Â   fixes the problem :            Â        [2][2][6]http://git.alsa-project.org/?p=alsa-...792dc809c9 08cc            Â        [3][3][7]http://git.alsa-project.org/?p=alsa-...5dc6e15942 91e7            Â   Then no more segfault in pulseaudio when accessing the USB            soundcard.            Â   Â            Â   Please could you fix it ?            Â   Â            Â   Regards            Â   jp            References            Â   Visible links            Â   1.            [4][8]https://www.linuxquestions.org/questions /slackware-14/current-fri            -oct-19-puseaudio-segfauts-4175640773/            Â   2.            [5][9]http://git.alsa-project.org/?p=alsa-plug ins.git;a=commitdiff;h=fc            3f5d51062ff438780e568995792dc809c908cc            Â   3.            [6][10]http://git.alsa-project.org/?p=alsa-plu gins.git;a=commitdiff;h=6b            996865126dd559ef186002e45dc6e1594291e7            Â   Hidden links:            Â   4.            [7][11]https://www.linuxquestions.org/question s/slackware-14/current-fri            -oct-19-puseaudio-segfauts-4175640773/            ______________________________________________ _            Alsa-devel mailing list            [8][12]Alsa-devel@xxxxxxxxxxxxxxxx      <mailto:[13]Alsa-devel@xxxxxxxxxxxxxxxx>            [9][14]http://mailman.alsa-project.org/mailman /listinfo/alsa-devel       References          1.      [15]https://www.linuxquestions.org/questions/slackware-14/ current-fri-oc          2. [16]http://git.alsa-project.org/?p=alsa-...792dc809c908cc          3. [17]http://git.alsa-project.org/?p=alsa-...5dc6e1594291e7          4.      [18]https://www.linuxquestions.org/questions/slackware-14/ current-fri-oct-19-puseaudio-segfauts-4175640773/          5.      [19]http://git.alsa-project.org/?p=alsa-plugins.git;a=comm itdiff;h=fc3f5d51062ff438780e568995792dc809c908cc          6.      [20]http://git.alsa-project.org/?p=alsa-plugins.git;a=comm itdiff;h=6b996865126dd559ef186002e45dc6e1594291e7          7.      [21]https://www.linuxquestions.org/questions/slackware-14/ current-fri-oct-19-puseaudio-segfauts-4175640773/          8. mailto:[22]Alsa-devel@xxxxxxxxxxxxxxxx      <mailto:[23]Alsa-devel@xxxxxxxxxxxxxxxx>          9. [24]http://mailman.alsa-project.org/mailman/listinfo/alsa-devel       _______________________________________________       Alsa-devel mailing list       [25]Alsa-devel@xxxxxxxxxxxxxxxx <mailto:[26]Alsa-devel@xxxxxxxxxxxxxxxx>       [27]http://mailman.alsa-project.org/mailman/listinfo/als a-devel          --  Jaroslav Kysela <[28]perex@xxxxxxxx <mailto:[29]perex@xxxxxxxx>>  Linux Sound Maintainer; ALSA Project; Red Hat, Inc.  _______________________________________________  Alsa-devel mailing list  [30]Alsa-devel@xxxxxxxxxxxxxxxx <mailto:[31]Alsa-devel@xxxxxxxxxxxxxxxx>  [32]http://mailman.alsa-project.org/mailman/listinfo/alsa-devel  -- Jaroslav Kysela <[33]perex@xxxxxxxx> Linux Sound Maintainer; ALSA Project; Red Hat, Inc. References 1. http://git.alsa-project.org/?p=alsa-plugins.git;a=commitdiff;h=a4e7e1282c57a2f4e83afe9a4008042d8b4c5bb9 2. mailto:perex@xxxxxxxx 3. mailto:h1p8r10n@xxxxxxxxxx 4. mailto:h1p8r10n@xxxxxxxxxx 5. https://www.linuxquestions.org/questions/slackware-14/cu 6. http://git.alsa-project.org/?p=alsa-...792dc809c908cc 7. http://git.alsa-project.org/?p=alsa-...5dc6e1594291e7 8. https://www.linuxquestions.org/questions/slackware-14/current-fri 9. http://git.alsa-project.org/?p=alsa-plugins.git;a=commitdiff;h=fc 10. http://git.alsa-project.org/?p=alsa-plugins.git;a=commitdiff;h=6b 11. https://www.linuxquestions.org/questions/slackware-14/current-fri 12. mailto:Alsa-devel@xxxxxxxxxxxxxxxx 13. mailto:Alsa-devel@xxxxxxxxxxxxxxxx 14. http://mailman.alsa-project.org/mailman/listinfo/alsa-devel 15. https://www.linuxquestions.org/questions/slackware-14/current-fri-oc 16. http://git.alsa-project.org/?p=alsa-...792dc809c908cc 17. http://git.alsa-project.org/?p=alsa-...5dc6e1594291e7 18. https://www.linuxquestions.org/questions/slackware-14/current-fri-oct-19-puseaudio-segfauts-4175640773/ 19. http://git.alsa-project.org/?p=alsa-plugins.git;a=commitdiff;h=fc3f5d51062ff438780e568995792dc809c908cc 20. http://git.alsa-project.org/?p=alsa-plugins.git;a=commitdiff;h=6b996865126dd559ef186002e45dc6e1594291e7 21. https://www.linuxquestions.org/questions/slackware-14/current-fri-oct-19-puseaudio-segfauts-4175640773/ 22. mailto:Alsa-devel@xxxxxxxxxxxxxxxx 23. mailto:Alsa-devel@xxxxxxxxxxxxxxxx 24. http://mailman.alsa-project.org/mailman/listinfo/alsa-devel 25. mailto:Alsa-devel@xxxxxxxxxxxxxxxx 26. mailto:Alsa-devel@xxxxxxxxxxxxxxxx 27. http://mailman.alsa-project.org/mailman/listinfo/alsa-devel 28. mailto:perex@xxxxxxxx 29. mailto:perex@xxxxxxxx 30. mailto:Alsa-devel@xxxxxxxxxxxxxxxx 31. mailto:Alsa-devel@xxxxxxxxxxxxxxxx 32. http://mailman.alsa-project.org/mailman/listinfo/alsa-devel 33. mailto:perex@xxxxxxxx _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel