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>
Instead of passing ambiguous integer array, define snd_pcm_chmap_t and
snd_pcm_chmap_query_t so that user can understand more easily which
element is for what.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Something that is allocated using calloc is not freed on an error path.
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Suman Saha <sumsaha@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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>
The mmap of multi plugin seems broken (for a long time!) due to its
creation of local buffer via snd_pcm_mmap(). Since the multi plugin
just needs to shadow the mmap buffer of each slave, it now has
mmap_shadow=1 and its own mmap/unmap method to do shadowing.
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 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.
- changed snd_config_get_id function to follow semantic of other get functions
- added snd_config_test_id
- added runtime pointer type (not persistent)
- added snd_config_make_pointer, snd_config_set_pointer, snd_config_get_pointer
- added type/contents checking for callback functions
- changed 'void *private_data' to 'snd_config_t *private_data'
- renamed card_strtype functions to card_driver
Control:
- fixed passing parameters to snd_ctl_async
Async handlers:
- added public snd_async_handler_get_signo function
Documentation:
- moved all documentation to source files
- added pcm.front, pcm.rear, pcm.center_lfe blocks
* Added configuration for EMU10K1 (it's fully working one!!!)
* snd_config_redirect_load->snd_config_refer_load rename
* snd_config_search_alias code change (works also with pairs base.key)
* cleanups in the evaluate function (the function prototype has been changed)
