The code in this library is far from self-explanatory, hopefully this
state diagram reverse-engineered from the code will help others
understand the expected transitions.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20220919121041.43463-3-pierre-louis.bossart@linux.intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
#include <sound/hda_register.h>
#include "trace.h"
+/*
+ * the hdac_stream library is intended to be used with the following
+ * transitions. The states are not formally defined in the code but loosely
+ * inspired by boolean variables. Note that the 'prepared' field is not used
+ * in this library but by the callers during the hw_params/prepare transitions
+ *
+ * |
+ * stream_init() |
+ * v
+ * +--+-------+
+ * | unused |
+ * +--+----+--+
+ * | ^
+ * stream_assign() | | stream_release()
+ * v |
+ * +--+----+--+
+ * | opened |
+ * +--+----+--+
+ * | ^
+ * stream_reset() | |
+ * stream_setup() | | stream_cleanup()
+ * v |
+ * +--+----+--+
+ * | prepared |
+ * +--+----+--+
+ * | ^
+ * stream_start() | | stream_stop()
+ * v |
+ * +--+----+--+
+ * | running |
+ * +----------+
+ */
+
/**
* snd_hdac_get_stream_stripe_ctl - get stripe control value
* @bus: HD-audio core bus