From f6161f379c5d455bcedc2cbb1968235a85e151c1 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Sun, 17 Nov 2019 09:53:04 +0100 Subject: 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 --- Documentation/sound/kernel-api/writing-an-alsa-driver.rst | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'Documentation/sound') 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 ~~~~~~~~~~~~~~~~~~~ -- cgit