snd_bcm2835 and Pulseaudio 5 do not get along

[maxnet]

I am having unreliable audio on a system that has Pulseaudio 5.0 installed.
It seems that when Pulseaudio is installed, and an application has finished playing audio, Pulseaudio doesn't close the audio device straight away, but waits 5 seconds.
If another application shows up that wants to play audio within that time, it re-uses the same connection.
However it seems that does not work properly on the Pi.

If I do:

aplay /usr/share/sounds/alsa/Front_Center.wav ; sleep 4 ; aplay /usr/share/sounds/alsa/Front_Center.wav

The file plays correctly the first time, but the second time there is no sound, and the program never finishes executing.
It just prints "Playing WAVE '/usr/share/sounds/alsa/Front_Center.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Mono", and sits there.
Problem doesn't happen when sleeping at least 5 seconds.

No idea how to debug this, and if the problem is in the ALSA module or in Pulseaudio.
But here is the output of bcm2835_snd with debugging enabled in case that is useful to anyone: https://paste.ee/r/soht7

Was able to reproduce the issue with both my own custom Linux distribution, and with Arch Linux (installed Pulse with: "pacman -Sy pulseaudio pulseaudio-alsa alsa-utils ; pulseaudio --start")
Doesn't seem to happen with very old versions of Pulse, like 2.0 which you get when you install it through Raspbian.

[tdaede]

I am having a similar problem with Pulseaudio 6.0. Pulseaudio tends to either not play at all, or lock up after a few minutes of playback. Also using Arch Linux. Have tried both user mode (running as root) as well as system mode, as I have the Pi set up headless.

[tdaede]

The following is the error printed by Pulseaudio whenever it hangs (after about a minute or two of playback, usually)

E: [alsa-sink-bcm2835 ALSA] alsa-sink.c: ALSA woke us up to write new data to the device, but there was actually nothing to write!
E: [alsa-sink-bcm2835 ALSA] alsa-sink.c: Most likely this is a bug in the ALSA driver '(null)'. Please report this issue to the ALSA developers.
E: [alsa-sink-bcm2835 ALSA] alsa-sink.c: We were woken up with POLLOUT set -- however a subsequent snd_pcm_avail() returned 0 or another value < min_avail.

[diamondman]

I too am having terrible issues with the bcm2835 and pulse 6.
If I start up pulseaudio and run paplay locally (on the pi), it starts immediately playing with the audio all garbled. Parts of the PCM sound like they are being played out of order. The longer the audio plays the worse it gets until the audio is almost pure noise.
Killing (CTRL+C) and running paplay subsequent times causes a repeatable pattern of garbling the audio or pure silence, till on the 8th run it plays the audio perfect. Play it again and the cycle restarts.
The pattern is garbled, silent, garbled, garbled, silent, garbled, silent, perfect.
If I use a USB headset paplay works every time.
I have had it where I have audio playing over the USB headset perfect, and then I unplug the usb dongle and audio plays correctly out of the analog port of the pi. Stop and restart audio and it will be garbled.

[flittermice]

My setup: pulseaudio+mpd+ncmpcpp.

My test setup is to start a song and play/pause repeatedly. After a maximum 3 times of play/pause pulseaudio will hang and has to be restarted.
This only happens on my Raspberry B+ with the bcm2835 chip, both with Debian and Arch based distributions. I have no problems with exactly the same setup on my desktop PC with an Intel sound chip. The problem did not exist with kernel 3.6 (but I don't want to use an ancient distribution).

None of the workarounds to be found on the web (tsched=0, disabling module-suspend-on-idle, ...) has worked. I'll finally give up on this issue because I didn't find a solution for more than a year now. Either I'll buy myself a Raspberry 2 or I'll use mpd with the ALSA backend, because that works great.

[Ruffio]

@maxnet has this issue been resolved? If yes, then please close this issue.

[flittermice]

I don't think so. It doesn't work with Raspberry 3 either (which is no wonder because it uses the same chip/driver: snd_bcm2835).

[pdtwonotes]

I have this problem on my Raspberry 3 running ubuntu 16.04. As a workaround I will put a 5 second timeout delay in my program, but that messes up the naturalness of the output (It is a speech synthesizer)

[nutpantz]

Same issue with my pi3 and ubuntu mate 16.04 and mpd sounds fantastic unless I change volume (which causes stuttering or sound loss) also looses sound randomly among other issues.really frustrating.

[jekhor]

Same issue at Rpi B (not 2 or 3) with latest kernel (684be4bc8cc343f60fdc3240c6d55d41d0a5b56c)

[andir]

Can confirm that issue with an rpi3 running Linux raspberrypi 4.9.27-v7+ #997 SMP Tue May 9 19:58:37 BST 2017 armv7l GNU/Linux on raspbian.. Pulseaudio usually stops playing between tracks that I feed to it from mpd (from another host via network). When trying to play 24bit flac audio via mpd to pulse it only plays 2 seconds and freezes..

[mweinelt]

Confirming issue on rpi3 running 4.9.30-v7+. Filling mpds playlist and starting playback will usually work until the playlist completes, but manually changing tracks, stopping and restarting, will stop the audio output from working, until I restart mpd.

audio_output {
        type            "alsa"
        name            "ALSA Output"
#       device          "hw:0,0"        # optional
        mixer_type      "software"      # optional
#       mixer_device    "default"       # optional
#       mixer_control   "PCM"           # optional
#       mixer_index     "0"             # optional
#       auto_resample   "no"
#       auto_channels   "no"
#       auto_format     "no"
}

[pjotrek-b]

Having the same problematic behavior as described by @flittermice 😞
System is RPi2 running a fresh install of Raspbian Stretch (9.1) with pulseaudio v10.0-1+deb9u1, kernel 4.9.59+
Been reading related articles/tutorials/threads, but MPD playback hangs as described above, until I kill-and-restart pulseaudio.

Has anyone found a solution to this yet? 🤞 😄

[pjotrek-b]

Found something interesting (maybe):
When pulseaudio hangs (as described above), issuing a "paplay" command twice (!) resumes audio playback:
$ paplay /usr/share/sounds/alsa/Front_Center.wav

• The 1st time, the paplay command times out (or can be interrupted by Ctrl+C)
• The 2nd time the paplay command works, and now sound from MPD is resumed.

Works for a random amount of time, then it's back to @flittermice's behavior 😭