snd_pcm_write_areas() tries to wait until avail >= avail_min condition
is satisfied. This doesn't work always well when a rate plugin is in
the play.
When a partial data with a smaller size than a period is written, the
rate plugin doesn't transfer the data immediately to the slave PCM,
but kept in an internal buffer and it changes only the hwptr of the
plugin. Thus, the condition "avail < avail_min" is triggered for a
wait check although the underlying slave PCM has enough room. This
results in a call of snd_pcm_wait() which returns immediately after
poll() call, and the snd_pcm_write_areas() loop continues. As a
consequence, it falls into a CPU hog.
This patch fixes that busy loop by introducing a new fast_ops to check
the availability for wait of avail_min. Then a plugin can ask the
slave PCM whether the wait is required (or possible).
A few plugins like multi plugin need a special handling. Otherwise a
generic plugin function can be used.
Reported-by: Trent Piepho <tpiepho@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
PulseAudio ALSA modules report errors after calling
snd_pcm_avail_delay(), with a delay lower than the number of samples
available.
Correct delay using Jaroslav's recommendation:
"the result should be 'delay(slave) + mmap_capture_avail(pcm)"
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@intel.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
plug->client_frames and plug->slave_frames are not used by
any plugin, remove dead code.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@intel.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
This ensures they are emitted in .data.rel.ro rather than .data.rel,
which should make a nice difference when using prelink.
Signed-off-by: Diego E. 'Flameeyes' Pettenò <flameeyes@gmail.com>
Make snd_pcm_plugin_rewind()/_forward() actually return how much has
been rewound/forwarded instead of how much could have been
rewounded/forwarded. This makes the code actually do what the
documentation of snd_pcm_rewind() suggests.
Signed-off-by: Lennart Poettering <lennart@poettering.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This minor patch fixes the type of the sframes variable in
snd_pcm_plugin_forward(). With this fix we need to cast less and the
code is less confusing.
Signed-off-by: Lennart Poettering <lennart@poettering.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The clamping of the input parameter in snd_pcm_rewind()/_forward() is
in the wrong direction.
Signed-off-by: Lennart Poettering <lennart@poettering.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Instead of link_fd, more generic callback link_slaves is introduced.
This is called for linking the slave streams as the source to the
given master stream.
- added link/unlink/link_fd fast_ops callbacks
- moved code from snd_pcm_link to pcm_hw.c
- moved "empty" routines pointing to slave to pcm_generic.c
- introduced snd_pcm_generic_t
Change the handling of non-fatal errors. Now the non-fatal error
messages are not shown in stderr and no assert() as default. The
behavior can be changed with LIBASOUND_DEBUG environment variable.
- added poll_events to main pcm structure
- added poll_revents callback to pcm->ops structure
- fixed snd_pcm_wait() - call revents function and enhanced
error code reporting
DMIX plugin:
- more complete code (works at least for one instance)
- still no "mix" code (it's silent)
More documentation updates for snd_pcm_avail_update() and snd_pcm_delay().
Updated behaviour of read/write functions (wait when buffer is full) to
follow kernel.
Added undo callbacks for snd_pcm_plugin based plugins.
- helpers when mmap_commit proceed only a partial transfer
Fixes to avail_update implementation in pcm_hw.c.
