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ALSA: docs: Update document about the default PCM ioctl ops 

Mention that it's completely optional now.

Link: https://lore.kernel.org/r/20191117085308.23915-5-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2019-11-17 09:53:04 +01:00
parent fc033cbf6f
commit f6161f379c
1 changed files with 4 additions and 4 deletions
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8
Documentation/sound/kernel-api/writing-an-alsa-driver.rst
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@ -1341,7 +1341,6 @@ shows only the skeleton, how to build up the PCM interfaces.
static struct snd_pcm_ops snd_mychip_playback_ops = {
.open = snd_mychip_playback_open,
.close = snd_mychip_playback_close,
.ioctl = snd_pcm_lib_ioctl,
.hw_params = snd_mychip_pcm_hw_params,
.hw_free = snd_mychip_pcm_hw_free,
.prepare = snd_mychip_pcm_prepare,
@ -1353,7 +1352,6 @@ shows only the skeleton, how to build up the PCM interfaces.
static struct snd_pcm_ops snd_mychip_capture_ops = {
.open = snd_mychip_capture_open,
.close = snd_mychip_capture_close,
.ioctl = snd_pcm_lib_ioctl,
.hw_params = snd_mychip_pcm_hw_params,
.hw_free = snd_mychip_pcm_hw_free,
.prepare = snd_mychip_pcm_prepare,
@ -1456,7 +1454,6 @@ The operators are defined typically like this:
static struct snd_pcm_ops snd_mychip_playback_ops = {
.open = snd_mychip_pcm_open,
.close = snd_mychip_pcm_close,
.ioctl = snd_pcm_lib_ioctl,
.hw_params = snd_mychip_pcm_hw_params,
.hw_free = snd_mychip_pcm_hw_free,
.prepare = snd_mychip_pcm_prepare,
@ -1913,7 +1910,10 @@ ioctl callback
~~~~~~~~~~~~~~
This is used for any special call to pcm ioctls. But usually you can
pass a generic ioctl callback, :c:func:`snd_pcm_lib_ioctl()`.
leave it as NULL, then PCM core calls the generic ioctl callback
function :c:func:`snd_pcm_lib_ioctl()`. If you need to deal with the
unique setup of channel info or reset procedure, you can pass your own
callback function here.
hw_params callback
~~~~~~~~~~~~~~~~~~~