ALSA: usbaudio: implement USB autosuspend

Devices are autosuspended if no pcm nor midi channel is open
Mixer devices may be opened. This way they are active when
in use to play or record sound, but can be suspended while
users have a mixer application running.

[Small clean-ups using static inline by tiwai]

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 15 insertions, 5 deletions

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index e3f680526cb5..b8dcbf407bbb 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -32,6 +32,7 @@
 #include "helper.h"
 #include "pcm.h"
 #include "clock.h"
+#include "power.h"
 
 /*
  * return the current pcm pointer.  just based on the hwptr_done value.
@@ -739,6 +740,9 @@ static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substre
                 pt = 125 * (1 << fp->datainterval);
                 ptmin = min(ptmin, pt);
         }
+        err = snd_usb_autoresume(subs->stream->chip);
+        if (err < 0)
+                return err;
 
         param_period_time_if_needed = SNDRV_PCM_HW_PARAM_PERIOD_TIME;
         if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL)
@@ -756,21 +760,21 @@ static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substre
                                        SNDRV_PCM_HW_PARAM_CHANNELS,
                                        param_period_time_if_needed,
                                        -1)) < 0)
-                return err;
+                goto rep_err;
         if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
                                        hw_rule_channels, subs,
                                        SNDRV_PCM_HW_PARAM_FORMAT,
                                        SNDRV_PCM_HW_PARAM_RATE,
                                        param_period_time_if_needed,
                                        -1)) < 0)
-                return err;
+                goto rep_err;
         if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
                                        hw_rule_format, subs,
                                        SNDRV_PCM_HW_PARAM_RATE,
                                        SNDRV_PCM_HW_PARAM_CHANNELS,
                                        param_period_time_if_needed,
                                        -1)) < 0)
-                return err;
+                goto rep_err;
         if (param_period_time_if_needed >= 0) {
                 err = snd_pcm_hw_rule_add(runtime, 0,
                                           SNDRV_PCM_HW_PARAM_PERIOD_TIME,
@@ -780,11 +784,15 @@ static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substre
                                           SNDRV_PCM_HW_PARAM_RATE,
                                           -1);
                 if (err < 0)
-                        return err;
+                        goto rep_err;
         }
         if ((err = snd_usb_pcm_check_knot(runtime, subs)) < 0)
-                return err;
+                goto rep_err;
         return 0;
+
+rep_err:
+        snd_usb_autosuspend(subs->stream->chip);
+        return err;
 }
 
 static int snd_usb_pcm_open(struct snd_pcm_substream *substream, int direction)
@@ -798,6 +806,7 @@ static int snd_usb_pcm_open(struct snd_pcm_substream *substream, int direction)
         runtime->hw = snd_usb_hardware;
         runtime->private_data = subs;
         subs->pcm_substream = substream;
+        /* runtime PM is also done there */
         return setup_hw_info(runtime, subs);
 }
 
@@ -811,6 +820,7 @@ static int snd_usb_pcm_close(struct snd_pcm_substream *substream, int direction)
                 subs->interface = -1;
         }
         subs->pcm_substream = NULL;
+        snd_usb_autosuspend(subs->stream->chip);
         return 0;
 }