This adds an api.alsa.bind-ctls property to alsa-pcm sink and source
nodes, to bind a property to an ALSA PCM ctl. The property is an array
of ctl names that should be bound.
This can be handy, for example, to bind the Playback/Capture Rate
controls on a USB gadget, in order to track the PCM's state via a node
param.
This is currently wired to be read-only, but it should be easy enough to
make it writable.
Because we now always _drop/_prepare_/_start, the snd_pcm_recover()
before that is no longer useful.
Retry snd_pcm_resume() after suspend when -EAGAIN and fall back to
_drop/_prepare/_start when that fails.
We need to disable the resampler when there is a pitch element. This was
correctly done in setup_matching but not in check_position_config().
See #3628
We calculate the available frames in read_sync but add another
check in read_frames so that we don't attempt to read more frames
than we have available to avoid xruns.
Make a function to recalculate the headroom and call it whenever the
resample state of the node can change.
When we are IRQ based scheduling but need to resample, we are actually
not driving the graph whit IRQ and need to adjust our period size and
headroom as if we are using timers.
All linked PCMs prepare together. If we prepare the secondaries, that
action clobbers the write pointer of every PCM every time, which then
causes playback to fail to start due to lack of data.
Signed-off-by: Hector Martin <marcan@marcan.st>
When the PCM is stopped, don't check for early wakeup because if we
are early, we will never be on time in the next iteration either because the
PCM is stopped and doesn't advance.
Also don't try to align when stopped.
See #3565
Add an option to automatically use snd_pcm_link when the follower clock
is matching the driver. Only set this to true in pro-audio and when
nodes are scheduled together.
See #3556
We only start the ALSA pcm after we get our first buffer.
We still need to do the sync through (and get the number of prefilled
samples) to make sure we set our new timeout and don't keep on waking
up quickly while the graph fetches the first buffer.
Rename some variables to make it clear that we are dealing with the rate
and duration of the driver.
Set the driver rate in the clock instead of the target_rate, which we
might have rejected.
When we are using the same clock (!matching) try to link the two PCM
devices together. This starts and stops the devices at the same time and
gives better latency.
Keep track or the follower state and do the sync from the driver
wakeup.
This improves sync between devices because the sync no longer
depends on when the node was woken up in the graph and scheduled. We
would have been able to handle this difference by using the htimestamp
but that doesn't seen to work reliably on some hardware.
This is also essential for the interrupt based scheduling.
Split the spa_alsa_start() in a prepare and start function. Prepare
will then also reset state and prefill the playback buffer with silence.
This makes it possible to reuse the prepare function in recover().
The threshold depends on the samplerate and even when the graph rate or
quantum didn't change, the driver could be opened in a different
samplerate, which would cause the timeouts to be wrong and cause xruns.
We're missing the delay in samples plus all of the extra samples of
silence we use to restart the device. This is in the samplerate of
the device.
Convert this to the time domain of the graph before adding it to xrun.
The default period is based on the default rate and might be too small
when using high samplerates. Scale the rate with the samplerate and make
sure it's a power of 2 to avoid trouble.
Fixes#3444
Add an xrun counter in the clock that accumulated the duration of
xruns. Fill this in in alsa-pcm.
A client could use this to dectect xruns (when it changes) and to align
the position and nsec after an xrun.
