These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / sound / usb / card.c

diff --git a/kernel/sound/usb/card.c b/kernel/sound/usb/card.c
index 0450593..1f09d95 100644 (file)
--- a/kernel/sound/usb/card.c
+++ b/kernel/sound/usb/card.c
@@ -365,13 +365,15 @@ static int snd_usb_audio_create(struct usb_interface *intf,
        }
 
        mutex_init(&chip->mutex);
-       init_rwsem(&chip->shutdown_rwsem);
+       init_waitqueue_head(&chip->shutdown_wait);
        chip->index = idx;
        chip->dev = dev;
        chip->card = card;
        chip->setup = device_setup[idx];
        chip->autoclock = autoclock;
-       chip->probing = 1;
+       atomic_set(&chip->active, 1); /* avoid autopm during probing */
+       atomic_set(&chip->usage_count, 0);
+       atomic_set(&chip->shutdown, 0);
 
        chip->usb_id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
                              le16_to_cpu(dev->descriptor.idProduct));
@@ -495,13 +497,13 @@ static int usb_audio_probe(struct usb_interface *intf,
        mutex_lock(&register_mutex);
        for (i = 0; i < SNDRV_CARDS; i++) {
                if (usb_chip[i] && usb_chip[i]->dev == dev) {
-                       if (usb_chip[i]->shutdown) {
+                       if (atomic_read(&usb_chip[i]->shutdown)) {
                                dev_err(&dev->dev, "USB device is in the shutdown state, cannot create a card instance\n");
                                err = -EIO;
                                goto __error;
                        }
                        chip = usb_chip[i];
-                       chip->probing = 1;
+                       atomic_inc(&chip->active); /* avoid autopm */
                        break;
                }
        }
@@ -561,8 +563,8 @@ static int usb_audio_probe(struct usb_interface *intf,
 
        usb_chip[chip->index] = chip;
        chip->num_interfaces++;
-       chip->probing = 0;
        usb_set_intfdata(intf, chip);
+       atomic_dec(&chip->active);
        mutex_unlock(&register_mutex);
        return 0;
 
@@ -570,7 +572,7 @@ static int usb_audio_probe(struct usb_interface *intf,
        if (chip) {
                if (!chip->num_interfaces)
                        snd_card_free(chip->card);
-               chip->probing = 0;
+               atomic_dec(&chip->active);
        }
        mutex_unlock(&register_mutex);
        return err;
@@ -585,23 +587,23 @@ static void usb_audio_disconnect(struct usb_interface *intf)
        struct snd_usb_audio *chip = usb_get_intfdata(intf);
        struct snd_card *card;
        struct list_head *p;
-       bool was_shutdown;
 
        if (chip == (void *)-1L)
                return;
 
        card = chip->card;
-       down_write(&chip->shutdown_rwsem);
-       was_shutdown = chip->shutdown;
-       chip->shutdown = 1;
-       up_write(&chip->shutdown_rwsem);
 
        mutex_lock(&register_mutex);
-       if (!was_shutdown) {
+       if (atomic_inc_return(&chip->shutdown) == 1) {
                struct snd_usb_stream *as;
                struct snd_usb_endpoint *ep;
                struct usb_mixer_interface *mixer;
 
+               /* wait until all pending tasks done;
+                * they are protected by snd_usb_lock_shutdown()
+                */
+               wait_event(chip->shutdown_wait,
+                          !atomic_read(&chip->usage_count));
                snd_card_disconnect(card);
                /* release the pcm resources */
                list_for_each_entry(as, &chip->pcm_list, list) {
@@ -631,28 +633,52 @@ static void usb_audio_disconnect(struct usb_interface *intf)
        }
 }
 
-#ifdef CONFIG_PM
-
-int snd_usb_autoresume(struct snd_usb_audio *chip)
+/* lock the shutdown (disconnect) task and autoresume */
+int snd_usb_lock_shutdown(struct snd_usb_audio *chip)
 {
-       int err = -ENODEV;
+       int err;
 
-       down_read(&chip->shutdown_rwsem);
-       if (chip->probing || chip->in_pm)
-               err = 0;
-       else if (!chip->shutdown)
-               err = usb_autopm_get_interface(chip->pm_intf);
-       up_read(&chip->shutdown_rwsem);
+       atomic_inc(&chip->usage_count);
+       if (atomic_read(&chip->shutdown)) {
+               err = -EIO;
+               goto error;
+       }
+       err = snd_usb_autoresume(chip);
+       if (err < 0)
+               goto error;
+       return 0;
 
+ error:
+       if (atomic_dec_and_test(&chip->usage_count))
+               wake_up(&chip->shutdown_wait);
        return err;
 }
 
+/* autosuspend and unlock the shutdown */
+void snd_usb_unlock_shutdown(struct snd_usb_audio *chip)
+{
+       snd_usb_autosuspend(chip);
+       if (atomic_dec_and_test(&chip->usage_count))
+               wake_up(&chip->shutdown_wait);
+}
+
+#ifdef CONFIG_PM
+
+int snd_usb_autoresume(struct snd_usb_audio *chip)
+{
+       if (atomic_read(&chip->shutdown))
+               return -EIO;
+       if (atomic_inc_return(&chip->active) == 1)
+               return usb_autopm_get_interface(chip->pm_intf);
+       return 0;
+}
+
 void snd_usb_autosuspend(struct snd_usb_audio *chip)
 {
-       down_read(&chip->shutdown_rwsem);
-       if (!chip->shutdown && !chip->probing && !chip->in_pm)
+       if (atomic_read(&chip->shutdown))
+               return;
+       if (atomic_dec_and_test(&chip->active))
                usb_autopm_put_interface(chip->pm_intf);
-       up_read(&chip->shutdown_rwsem);
 }
 
 static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
@@ -665,30 +691,20 @@ static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
        if (chip == (void *)-1L)
                return 0;
 
-       if (!PMSG_IS_AUTO(message)) {
+       chip->autosuspended = !!PMSG_IS_AUTO(message);
+       if (!chip->autosuspended)
                snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
-               if (!chip->num_suspended_intf++) {
-                       list_for_each_entry(as, &chip->pcm_list, list) {
-                               snd_pcm_suspend_all(as->pcm);
-                               as->substream[0].need_setup_ep =
-                                       as->substream[1].need_setup_ep = true;
-                       }
-                       list_for_each(p, &chip->midi_list) {
-                               snd_usbmidi_suspend(p);
-                       }
+       if (!chip->num_suspended_intf++) {
+               list_for_each_entry(as, &chip->pcm_list, list) {
+                       snd_pcm_suspend_all(as->pcm);
+                       as->substream[0].need_setup_ep =
+                               as->substream[1].need_setup_ep = true;
                }
-       } else {
-               /*
-                * otherwise we keep the rest of the system in the dark
-                * to keep this transparent
-                */
-               if (!chip->num_suspended_intf++)
-                       chip->autosuspended = 1;
-       }
-
-       if (chip->num_suspended_intf == 1)
+               list_for_each(p, &chip->midi_list)
+                       snd_usbmidi_suspend(p);
                list_for_each_entry(mixer, &chip->mixer_list, list)
                        snd_usb_mixer_suspend(mixer);
+       }
 
        return 0;
 }
@@ -705,7 +721,7 @@ static int __usb_audio_resume(struct usb_interface *intf, bool reset_resume)
        if (--chip->num_suspended_intf)
                return 0;
 
-       chip->in_pm = 1;
+       atomic_inc(&chip->active); /* avoid autopm */
        /*
         * ALSA leaves material resumption to user space
         * we just notify and restart the mixers
@@ -725,7 +741,7 @@ static int __usb_audio_resume(struct usb_interface *intf, bool reset_resume)
        chip->autosuspended = 0;
 
 err_out:
-       chip->in_pm = 0;
+       atomic_dec(&chip->active); /* allow autopm after this point */
        return err;
 }