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ALSA: Remove transfer_ack_{begin,end} callbacks from struct snd_pcm_runtime 

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been superseded by newer alsa-driver releases.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>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
(cherry picked from commit 53e597b1d194910bef53ed0632da329fef497904)

Change-Id: Ifa69c873640b171aa1843335b2b3cb856d29bb1a
This commit is contained in:
Lars-Peter Clausen 2015-10-22 11:11:56 +00:00 committed by Sean McCreary
parent 97b270d974
commit 602366ce81
3 changed files with 2 additions and 26 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
Documentation/DocBook/writing-an-alsa-driver.tmpl
View File

@ -2221,10 +2221,6 @@ 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 */
@ -2249,9 +2245,8 @@ 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>
@ -2578,16 +2573,6 @@ 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">

4
include/sound/pcm.h
View File

@ -341,10 +341,6 @@ 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 */

5
sound/core/pcm_lib.c
View File

@ -1753,9 +1753,6 @@ 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)
@ -1765,8 +1762,6 @@ void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
snd_timer_interrupt(substream->timer, 1);
_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);
}