While there is nothing wrong with the transfer_ack_begin and transfer_ack_end callbacks per-se, the last documented user was part of the alsa-driver 0.5.12a package, which was released 14 years ago and even predates the upstream integration of the ALSA core and has subsequently been superseded by newer alsa-driver releases.
This seems to indicate that there is no need for having these callbacks and they are just cruft that can be removed.
Signed-off-by: Lars-Peter Clausen lars@metafoo.de --- Documentation/DocBook/writing-an-alsa-driver.tmpl | 19 ++----------------- include/sound/pcm.h | 4 ---- sound/core/pcm_lib.c | 5 ----- 3 files changed, 2 insertions(+), 26 deletions(-)
diff --git a/Documentation/DocBook/writing-an-alsa-driver.tmpl b/Documentation/DocBook/writing-an-alsa-driver.tmpl index 84ef6a9..a27ab9f5 100644 --- a/Documentation/DocBook/writing-an-alsa-driver.tmpl +++ b/Documentation/DocBook/writing-an-alsa-driver.tmpl @@ -2181,10 +2181,6 @@ struct _snd_pcm_runtime { struct snd_pcm_hardware hw; struct snd_pcm_hw_constraints hw_constraints;
- /* -- interrupt callbacks -- */ - void (*transfer_ack_begin)(struct snd_pcm_substream *substream); - void (*transfer_ack_end)(struct snd_pcm_substream *substream); - /* -- timer -- */ unsigned int timer_resolution; /* timer resolution */
@@ -2209,9 +2205,8 @@ struct _snd_pcm_runtime { For the operators (callbacks) of each sound driver, most of these records are supposed to be read-only. Only the PCM middle-layer changes / updates them. The exceptions are - the hardware description (hw), interrupt callbacks - (transfer_ack_xxx), DMA buffer information, and the private - data. Besides, if you use the standard buffer allocation + the hardware description (hw) DMA buffer information and the + private data. Besides, if you use the standard buffer allocation method via <function>snd_pcm_lib_malloc_pages()</function>, you don't need to set the DMA buffer information by yourself. </para> @@ -2538,16 +2533,6 @@ struct _snd_pcm_runtime { </para> </section>
- <section id="pcm-interface-runtime-intr"> - <title>Interrupt Callbacks</title> - <para> - The field <structfield>transfer_ack_begin</structfield> and - <structfield>transfer_ack_end</structfield> are called at - the beginning and at the end of - <function>snd_pcm_period_elapsed()</function>, respectively. - </para> - </section> - </section>
<section id="pcm-interface-operators"> diff --git a/include/sound/pcm.h b/include/sound/pcm.h index 2882ddd..3e0ffd2 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -402,10 +402,6 @@ struct snd_pcm_runtime { struct snd_pcm_hardware hw; struct snd_pcm_hw_constraints hw_constraints;
- /* -- interrupt callbacks -- */ - void (*transfer_ack_begin)(struct snd_pcm_substream *substream); - void (*transfer_ack_end)(struct snd_pcm_substream *substream); - /* -- timer -- */ unsigned int timer_resolution; /* timer resolution */ int tstamp_type; /* timestamp type */ diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 6dc4277..05a3ca9 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -1875,9 +1875,6 @@ void snd_pcm_period_elapsed(struct snd_pcm_substream *substream) return; runtime = substream->runtime;
- if (runtime->transfer_ack_begin) - runtime->transfer_ack_begin(substream); - snd_pcm_stream_lock_irqsave(substream, flags); if (!snd_pcm_running(substream) || snd_pcm_update_hw_ptr0(substream, 1) < 0) @@ -1889,8 +1886,6 @@ void snd_pcm_period_elapsed(struct snd_pcm_substream *substream) #endif _end: snd_pcm_stream_unlock_irqrestore(substream, flags); - if (runtime->transfer_ack_end) - runtime->transfer_ack_end(substream); kill_fasync(&runtime->fasync, SIGIO, POLL_IN); }