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authorTakashi Iwai <tiwai@suse.de>2019-11-17 11:53:04 +0300
committerTakashi Iwai <tiwai@suse.de>2019-11-20 21:39:54 +0300
commitf6161f379c5d455bcedc2cbb1968235a85e151c1 (patch)
treea6ad1e75aac3b7237887026bc1286a24b0d831c4 /Documentation/sound
parentfc033cbf6fb75452f03774ca5adccac8cf9bc84f (diff)
downloadlinux-f6161f379c5d455bcedc2cbb1968235a85e151c1.tar.xz
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>
Diffstat (limited to 'Documentation/sound')
-rw-r--r--Documentation/sound/kernel-api/writing-an-alsa-driver.rst8
1 files changed, 4 insertions, 4 deletions
diff --git a/Documentation/sound/kernel-api/writing-an-alsa-driver.rst b/Documentation/sound/kernel-api/writing-an-alsa-driver.rst
index 1086b35db2af..145bf6aad7cb 100644
--- a/Documentation/sound/kernel-api/writing-an-alsa-driver.rst
+++ b/Documentation/sound/kernel-api/writing-an-alsa-driver.rst
@@ -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
~~~~~~~~~~~~~~~~~~~