CVS commit: [netbsd-9] src/sys/dev/audio

["Martin Husemann" <martin%netbsd.org@localhost>]

Module Name:    src
Committed By:   martin
Date:           Mon Mar  1 16:00:08 UTC 2021

Modified Files:
        src/sys/dev/audio [netbsd-9]: audio.c

Log Message:
Pull up following revision(s) (requested by isaki in ticket #1219):

        sys/dev/audio/audio.c: revision 1.89
        sys/dev/audio/audio.c: revision 1.90
        sys/dev/audio/audio.c: revision 1.91

Change the lock conditions to call audio_unlink().

This can remove a different copy of audio_exlock_enter() in audio_unlink()
and can use normal one.  Also, in audiodetach(), this can set the exlock
at more natual order (before calling audio_unlink()).

No noticeable functional changes are intended.
Thanks for comments, riastradh@.

Protect also audioopen() and audiobellopen() from audiodetach() with
psref(9), as well as others(audioread, audiowrite, etc..).
- Rename audio_file_enter to audio_sc_acquire_fromfile, audio_file_exit
  to audio_sc_release, for clarify.  These are the reference counter for
  this sc.
- Introduce audio_sc_acquire_foropen for audio{,bell}open.
- audio_open needs to examine sc_dying again before inserting it into
  sc_files, in order to keep sc_files consistency.

The race between audiodetach and audioopen is pointed out by riastradh@.
Thank you for many advices.

Add missing curlwp_bindx() corresponding to curlwp_bind().
Pointed out by riastradh@.


To generate a diff of this commit:
cvs rdiff -u -r1.28.2.20 -r1.28.2.21 src/sys/dev/audio/audio.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.