Hi,
This patchset includes a part of my former RFC: [alsa-devel] [PATCH RFC 00/21] ALSA: pcm: add tracepoints for PCM params operation http://mailman.alsa-project.org/pipermail/alsa-devel/2017-May/120548.html
The purpose of this patchset is to limit added events of tracepoint for PCM parameters only when corresponding parameter is actually changed. Developers get the events without events for unchanged parameters.
Additionally, this simplifies error handling of PCM parameters processing. This is intrusive somehow for userspace applications but just for error path.
Takashi Sakamoto (2): ALSA: pcm: return error immediately for parameters handling ALSA: pcm: probe events when parameters are changed actually
sound/core/pcm_native.c | 122 ++++++++++++++++++++++++++---------------------- 1 file changed, 67 insertions(+), 55 deletions(-)