[PATCH 0/2] [Jaunty] LP: #190754, #235990, #320875, #330814, #333565, #344057, #343254 -- Fix hw_ptr instability causing abysmal PulseAudio performance

[Tim Gardner]

Daniel T Chen wrote:
> hw_ptr tracking and calculations have been broken for quite some time in
> ALSA-kernel. The effects have been apparent: throughout 8.10 and 9.04
> development (particularly during the latter), users have complained of
> crackling and popping in a variety of drivers and applications. The
> popularity of HDA codecs and the advent of PulseAudio have exposed
> instability in hw_ptr and wrong assumptions in delay calculations.
> Indeed, PulseAudio has been arguably the worst victim, experiencing
> crashes and generating copious syslog debugging output among other
> regressions.
> 
> The two changesets from my for-kernel-team branch are backported from
> Takashi's sound-2.6 tree and are queued for inclusion in 2.6.30.
> 
> These changes have been well tested in my custom builds on
> kernel.ubuntu.com/~dtchen and have received extremely positive feedback.
> - From all indications, there are no regressions from behaviour using
> direct ALSA and JACK in previous Ubuntu releases, and PulseAudio
> behaviour is markedly improved.
> 
> Please apply to Jaunty.
> 
> Daniel T Chen (2):
>    UBUNTU: Don't trust hw-ptr blindly
>    UBUNTU: Apply further pcm_lib updates for hw_ptr
> 
>   sound/core/pcm_lib.c |  141 
> +++++++++++++++++++++++++++++++++-----------------
>   1 files changed, 94 insertions(+), 47 deletions(-)

Applied

https://bugs.edge.launchpad.net/ubuntu/jaunty/+source/linux/+bug/330814/comments/41

-- 
Tim Gardner tim.gardner at canonical.com