From: Takashi Sakamoto Date: Sat, 13 Aug 2016 01:13:33 +0000 (+0900) Subject: ALSA: seq: add documentation for snd_seq_kernel_client_ctl X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=77dfa8d3196a0cd219dfd6c65e4ff5a3e696fd8c;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git ALSA: seq: add documentation for snd_seq_kernel_client_ctl This kernel API is used by kernel implementation. Currently, it's used for kernel clients of ALSA sequencer, while it can be used for application clients. The difference is just on address spaces of argument. In short, this kernel API can be available for application client with data in kernel space. This commit adds a document about this. Signed-off-by: Takashi Sakamoto Signed-off-by: Takashi Iwai --- diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c index d6d9419d8bac..37590f8320a3 100644 --- a/sound/core/seq/seq_clientmgr.c +++ b/sound/core/seq/seq_clientmgr.c @@ -2423,9 +2423,17 @@ int snd_seq_kernel_client_dispatch(int client, struct snd_seq_event * ev, EXPORT_SYMBOL(snd_seq_kernel_client_dispatch); -/* - * exported, called by kernel clients to perform same functions as with - * userland ioctl() +/** + * snd_seq_kernel_client_ctl - operate a command for a client with data in + * kernel space. + * @clientid: A numerical ID for a client. + * @cmd: An ioctl(2) command for ALSA sequencer operation. + * @arg: A pointer to data in kernel space. + * + * Against its name, both kernel/application client can be handled by this + * kernel API. A pointer of 'arg' argument should be in kernel space. + * + * Return: 0 at success. Negative error code at failure. */ int snd_seq_kernel_client_ctl(int clientid, unsigned int cmd, void *arg) {