+ <para>
+ If the driver supports the suspend/resume
+ <emphasis>fully</emphasis>, that is, the device can be
+ properly resumed to the status at the suspend is called,
+ you can set <constant>SNDRV_PCM_INFO_RESUME</constant> flag
+ to pcm info field. Usually, this is possible when the
+ registers of ths chip can be safely saved and restored to the
+ RAM. If this is set, the trigger callback is called with
+ <constant>SNDRV_PCM_TRIGGER_RESUME</constant> after resume
+ callback is finished.
+ </para>
+
+ <para>
+ Even if the driver doesn't support PM fully but only the
+ partial suspend/resume is possible, it's still worthy to
+ implement suspend/resume callbacks. In such a case, applications
+ would reset the status by calling
+ <function>snd_pcm_prepare()</function> and restart the stream
+ appropriately. Hence, you can define suspend/resume callbacks
+ below but don't set <constant>SNDRV_PCM_INFO_RESUME</constant>
+ info flag to the PCM.
+ </para>
+
+ <para>
+ Note that the trigger with SUSPEND can be always called when
+ <function>snd_pcm_suspend_all</function> is called,
+ regardless of <constant>SNDRV_PCM_INFO_RESUME</constant> flag.
+ The <constant>RESUME</constant> flag affects only the behavior
+ of <function>snd_pcm_resume()</function>.
+ (Thus, in theory,
+ <constant>SNDRV_PCM_TRIGGER_RESUME</constant> isn't needed
+ to be handled in the trigger callback when no
+ <constant>SNDRV_PCM_INFO_RESUME</constant> flag is set. But,
+ it's better to keep it for compatibility reason.)
+ </para>