From 9f1614aae59033b79941220f65ad36f5fe54a579 Mon Sep 17 00:00:00 2001 From: Markus Pargmann Date: Fri, 11 Oct 2013 12:11:02 +0200 Subject: ASoC: snd_soc_dai_ops trigger function description Add a comment to the trigger function in snd_soc_dai_ops struct about possible command sequences. Signed-off-by: Markus Pargmann Signed-off-by: Mark Brown --- include/sound/soc-dai.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/sound') diff --git a/include/sound/soc-dai.h b/include/sound/soc-dai.h index ae9a227d35d3..0f2e5daa1451 100644 --- a/include/sound/soc-dai.h +++ b/include/sound/soc-dai.h @@ -166,6 +166,13 @@ struct snd_soc_dai_ops { struct snd_soc_dai *); int (*prepare)(struct snd_pcm_substream *, struct snd_soc_dai *); + /* + * NOTE: Commands passed to the trigger function are not necessarily + * compatible with the current state of the dai. For example this + * sequence of commands is possible: START STOP STOP. + * So do not unconditionally use refcounting functions in the trigger + * function, e.g. clk_enable/disable. + */ int (*trigger)(struct snd_pcm_substream *, int, struct snd_soc_dai *); int (*bespoke_trigger)(struct snd_pcm_substream *, int, -- cgit v1.2.3-59-g8ed1b