[pulseaudio-discuss] [PATCH] pulse: Fix invalid buffer pointer return value

[David Henningsson]

Colin Guthrie wrote:
> 'Twas brillig, and David Henningsson at 09/01/10 09:00 did gyre and gimble:
>> The pulse ALSA plugin has been known, for a while, to not work properly,
>> causing underruns, hangs etc. I sat down yesterday trying to figure it
>> out, and I'm pretty certain this patch improves the situation, but I
>> don't mind getting some help testing it before it is committed upstream.
>>
>> Related bug: https://bugs.launchpad.net/bugs/485488
>>
>> The patch is for the alsa-plugins tree at git.alsa-projects.org.
> 
> I applied this to 1.0.22 (cleanly) and sadly it's not helping my test
> case using mpg123.
> 
> I'm sure you've discussed the problem with Daniel (who pointed me at
> mpg123 in the first place), but I do still get crazy startups. It seems
> to be pretty stable after startup tho', so it's maybe just an
> initialisation issue?
> 
> Before the patch mpg123 would hang once in a while. I've tried to get it
> to do the same after the patch, but so far it's not hung so I think
> after the initial startup it does seem to stablise better than before.
> 
> Now there are of course potential bugs in mpg123's alsa implem. I've not
> looked at this at all - just using it blindly as a test case.

Actually, I was unaware of the mpg123 issue, and if you say it neither
makes the startups better or worse, I think that is something else. I've
never heard that kind of trouble in any other application either.

As for mpg123, it uses these sw parameters:
snd_pcm_sw_params_set_start_threshold(pcm, sw, 1)
snd_pcm_sw_params_set_avail_min(pcm, sw, 1)

...but that is perhaps not enough to explain the problem.

My own test case was FluidSynth, and people in the bug link above have
other test cases.

// David