[ALSA] usb audio suspend support
This patch implements suspend/resume support for USB audio devices.
It works with the microphone in my camera.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index 967b823..c52461d 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -2077,6 +2077,8 @@
static int usb_audio_probe(struct usb_interface *intf,
const struct usb_device_id *id);
static void usb_audio_disconnect(struct usb_interface *intf);
+static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message);
+static int usb_audio_resume(struct usb_interface *intf);
static struct usb_device_id usb_audio_ids [] = {
#include "usbquirks.h"
@@ -2092,6 +2094,8 @@
.name = "snd-usb-audio",
.probe = usb_audio_probe,
.disconnect = usb_audio_disconnect,
+ .suspend = usb_audio_suspend,
+ .resume = usb_audio_resume,
.id_table = usb_audio_ids,
};
@@ -3654,6 +3658,43 @@
dev_get_drvdata(&intf->dev));
}
+static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
+{
+ struct snd_usb_audio *chip = dev_get_drvdata(&intf->dev);
+ struct list_head *p;
+ struct snd_usb_stream *as;
+
+ if (chip == (void *)-1L)
+ return 0;
+
+ snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
+ if (!chip->num_suspended_intf++) {
+ list_for_each(p, &chip->pcm_list) {
+ as = list_entry(p, struct snd_usb_stream, list);
+ snd_pcm_suspend_all(as->pcm);
+ }
+ }
+
+ return 0;
+}
+
+static int usb_audio_resume(struct usb_interface *intf)
+{
+ struct snd_usb_audio *chip = dev_get_drvdata(&intf->dev);
+
+ if (chip == (void *)-1L)
+ return 0;
+ if (--chip->num_suspended_intf)
+ return 0;
+ /*
+ * ALSA leaves material resumption to user space
+ * we just notify
+ */
+
+ snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
+
+ return 0;
+}
static int __init snd_usb_audio_init(void)
{