Hi,
This is an update version of my previous patchset.
[alsa-devel] [PATCH 0/3] ALSA: pcm: add 'applptr' event of tracepoint http://mailman.alsa-project.org/pipermail/alsa-devel/2017-June/121657.html
Chagnes from v1: - rewrite change log for second patch, including content of cover letter in my previous patchset, according to advice from maintainer.
In design of ALSA PCM core, both of hardware-side and application-side position on PCM buffer are maintained as a part of information for runtime of PCM substream. In a view of ALSA PCM application, these two positions can be updated by executing ioctl(2) with some commands.
There's an event of tracepoint for hardware-side position; 'hwptr'. On the other hand, no events for application-side position.
This patchset adds a new event for this purpose; 'applptr'. When the application-side position is changed in kernel space, this event is probed with useful information for developers.
The event is not probed for all of ALSA PCM applications, In detail, please read second patch.
Takashi Sakamoto (3): ALSA: pcm: unify codes to operate application-side position on PCM buffer ALSA: pcm: add 'applptr' event of tracepoint ALSA: pcm: use %s instead of %c for format of PCM buffer tracepoints
sound/core/pcm_lib.c | 31 +++++++++++++++++++++++++++--- sound/core/pcm_local.h | 2 ++ sound/core/pcm_native.c | 28 ++++----------------------- sound/core/pcm_trace.h | 50 +++++++++++++++++++++++++++++++++++++++++++------ 4 files changed, 78 insertions(+), 33 deletions(-)