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 <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/include/sound/soc-dai.h b/include/sound/soc-dai.h
index ae9a227..0f2e5da 100644
--- a/include/sound/soc-dai.h
+++ b/include/sound/soc-dai.h
@@ -166,6 +166,13 @@
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,