Re: kern/54229: audio in firefox stops playing

[Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>]

The following reply was made to PR kern/54229; it has been noted by GNATS.

From: Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: coypu%sdf.org@localhost, tsutsui%ceres.dti.ne.jp@localhost
Subject: Re: kern/54229: audio in firefox stops playing
Date: Sun, 2 Jun 2019 03:06:22 +0900

 >  >  please don't remove this feature.
 >  >  
 >  >  i've used it infrequently over the years and i'm fairly sure i have
 >  >  at least one script that relies upon it (even though they could be
 >  >  rewritten.)
 >  
 >  In the name of "backwards compatibility" we'll have to change every
 >  single program using OSS audio in pkgsrc not to use /dev/sound.
 >  If someone keeps using an old program they'll have unexpected behaviour.
 >  
 >  That is the opposite result from the intention of backwards
 >  compatibility: old code works without modification.
 
 What behavior and/or which version's behavior are you trying to
 keep compatibility?
 
 According to analysis by isaki-san, the firefox problem also
 happens on 8.99.37 and NetBSD 8.x (i.e. pre isaki-audio2 merge):
 
 >>  1. boot any of
 >>     * NetBSD 8 or
 >>     * -current before merging isaki-audio2 (<8.99.39) or
 >>     * -current after merging isaki-audio2 (>=8.99.39).
 >>     (I think NetBSD7 is the same but I haven't confirmed)
 >>  2. audioctl -d /dev/sound -w play.pause=1
 >>  3. execute firefox and play something on youtube.
 >>     -> firefox cannot play video.
 
 On "3.", firefox reopen /dev/sound, as a device for OSS.
 Then the pause state (in AUDIO_SETINFO) set on "2." is
 kept and valid at "3.", per defined behavior of /dev/sound
 as mentioned in audio(4):
 
  https://netbsd.gw.com/cgi-bin/man-cgi?audio+4+NetBSD-8.0
 >> When /dev/sound is opened, it maintains the audio format
 >> and pause/unpause state of the most recently opened track.
 >> In all other respects /dev/audio and /dev/sound are identical.
 
 That's what isaki-san pointed out:
 
 >>  Unless firefox expects that it stops by external operation, I think
 >>  that using /dev/sound in firefox is a bug, although I'm not sure
 >>  about pkgsrc/www/firefox history.
 
 I guess the problem did not arise on NetBSD 7.x and prior
 by chance because other program could not open /dev/sound
 if firefox already opened it.
 
 ---
 Izumi Tsutsui