ALSA: usb-audio: work around Android accessory firmware bug

[pandora-kernel.git] / sound / usb / card.c

diff --git a/sound/usb/card.c b/sound/usb/card.c
index 05c1aae..3b79a4a 100644 (file)
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -47,6 +47,7 @@
 #include <linux/mutex.h>
 #include <linux/usb/audio.h>
 #include <linux/usb/audio-v2.h>
+#include <linux/module.h>
 
 #include <sound/control.h>
 #include <sound/core.h>
@@ -148,14 +149,32 @@ static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int int
                return -EINVAL;
        }
 
+       alts = &iface->altsetting[0];
+       altsd = get_iface_desc(alts);
+
+       /*
+        * Android with both accessory and audio interfaces enabled gets the
+        * interface numbers wrong.
+        */
+       if ((chip->usb_id == USB_ID(0x18d1, 0x2d04) ||
+            chip->usb_id == USB_ID(0x18d1, 0x2d05)) &&
+           interface == 0 &&
+           altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
+           altsd->bInterfaceSubClass == USB_SUBCLASS_VENDOR_SPEC) {
+               interface = 2;
+               iface = usb_ifnum_to_if(dev, interface);
+               if (!iface)
+                       return -EINVAL;
+               alts = &iface->altsetting[0];
+               altsd = get_iface_desc(alts);
+       }
+
        if (usb_interface_claimed(iface)) {
                snd_printdd(KERN_INFO "%d:%d:%d: skipping, already claimed\n",
                                                dev->devnum, ctrlif, interface);
                return -EINVAL;
        }
 
-       alts = &iface->altsetting[0];
-       altsd = get_iface_desc(alts);
        if ((altsd->bInterfaceClass == USB_CLASS_AUDIO ||
             altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) &&
            altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {
@@ -335,7 +354,7 @@ static int snd_usb_audio_create(struct usb_device *dev, int idx,
                return -ENOMEM;
        }
 
-       mutex_init(&chip->shutdown_mutex);
+       init_rwsem(&chip->shutdown_rwsem);
        chip->index = idx;
        chip->dev = dev;
        chip->card = card;
@@ -554,9 +573,11 @@ static void snd_usb_audio_disconnect(struct usb_device *dev,
                return;
 
        card = chip->card;
-       mutex_lock(&register_mutex);
-       mutex_lock(&chip->shutdown_mutex);
+       down_write(&chip->shutdown_rwsem);
        chip->shutdown = 1;
+       up_write(&chip->shutdown_rwsem);
+
+       mutex_lock(&register_mutex);
        chip->num_interfaces--;
        if (chip->num_interfaces <= 0) {
                snd_card_disconnect(card);
@@ -573,11 +594,9 @@ static void snd_usb_audio_disconnect(struct usb_device *dev,
                        snd_usb_mixer_disconnect(p);
                }
                usb_chip[chip->index] = NULL;
-               mutex_unlock(&chip->shutdown_mutex);
                mutex_unlock(&register_mutex);
                snd_card_free_when_closed(card);
        } else {
-               mutex_unlock(&chip->shutdown_mutex);
                mutex_unlock(&register_mutex);
        }
 }
@@ -609,16 +628,22 @@ int snd_usb_autoresume(struct snd_usb_audio *chip)
 {
        int err = -ENODEV;
 
-       if (!chip->shutdown && !chip->probing)
+       down_read(&chip->shutdown_rwsem);
+       if (chip->probing)
+               err = 0;
+       else if (!chip->shutdown)
                err = usb_autopm_get_interface(chip->pm_intf);
+       up_read(&chip->shutdown_rwsem);
 
        return err;
 }
 
 void snd_usb_autosuspend(struct snd_usb_audio *chip)
 {
+       down_read(&chip->shutdown_rwsem);
        if (!chip->shutdown && !chip->probing)
                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)