ALSA: usb-audio: Fix kernel panic of Digidesign Mbox2 quirk

This patch is based on 3.8-rc1. It fixes two things:
1) A kernel panic caused by incorrect allocation of a u8 variable
   "bootresponse".
2) A noisy dmesg (urb status -32) caused by broken pipe to an
   invalid midi endpoint.

It is also a little cleaner because there is no need for a new
QUIRK_MIDI type as suggested by kernel developers, since the device
follows exactly the MIDIMAN protocol.

Signed-off-by: Damien Zammit <damien@zamaudio.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

4 files changed, 8 insertions, 15 deletions

diff --git a/sound/usb/midi.c b/sound/usb/midi.c
index c183d34842ac..34b9bb7fe87c 100644
--- a/sound/usb/midi.c
+++ b/sound/usb/midi.c
@@ -2181,10 +2181,6 @@ int snd_usbmidi_create(struct snd_card *card,
                 umidi->usb_protocol_ops = &snd_usbmidi_novation_ops;
                 err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);
                 break;
-        case QUIRK_MIDI_MBOX2:
-                umidi->usb_protocol_ops = &snd_usbmidi_midiman_ops;
-                err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);
-                break;
         case QUIRK_MIDI_RAW_BYTES:
                 umidi->usb_protocol_ops = &snd_usbmidi_raw_ops;
                 /*
diff --git a/sound/usb/quirks-table.h b/sound/usb/quirks-table.h
index 5388ca3a4ab0..78e845ec65da 100644
--- a/sound/usb/quirks-table.h
+++ b/sound/usb/quirks-table.h
@@ -3015,7 +3015,7 @@ YAMAHA_DEVICE(0x7010, "UB99"),
                         },
                         {
                                 .ifnum = 6,
-                                .type = QUIRK_MIDI_MBOX2,
+                                .type = QUIRK_MIDI_MIDIMAN,
                                 .data = &(const struct snd_usb_midi_endpoint_info) {
                                         .out_ep =  0x02,
                                         .out_cables = 0x0001,
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index f104c68fe1e0..acc12f004c23 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -306,7 +306,6 @@ int snd_usb_create_quirk(struct snd_usb_audio *chip,
                 [QUIRK_MIDI_YAMAHA] = create_any_midi_quirk,
                 [QUIRK_MIDI_MIDIMAN] = create_any_midi_quirk,
                 [QUIRK_MIDI_NOVATION] = create_any_midi_quirk,
-                [QUIRK_MIDI_MBOX2] = create_any_midi_quirk,
                 [QUIRK_MIDI_RAW_BYTES] = create_any_midi_quirk,
                 [QUIRK_MIDI_EMAGIC] = create_any_midi_quirk,
                 [QUIRK_MIDI_CME] = create_any_midi_quirk,
@@ -528,11 +527,11 @@ static void mbox2_setup_48_24_magic(struct usb_device *dev)
 #define MBOX2_BOOT_LOADING     0x01 /* Hard coded into the device */
 #define MBOX2_BOOT_READY       0x02 /* Hard coded into the device */
 
-int snd_usb_mbox2_boot_quirk(struct usb_device *dev)
+static int snd_usb_mbox2_boot_quirk(struct usb_device *dev)
 {
         struct usb_host_config *config = dev->actconfig;
         int err;
-        u8 bootresponse;
+        u8 bootresponse[12];
         int fwsize;
         int count;
 
@@ -546,20 +545,20 @@ int snd_usb_mbox2_boot_quirk(struct usb_device *dev)
         snd_printd("usb-audio: Sending Digidesign Mbox 2 boot sequence...\n");
 
         count = 0;
-        bootresponse = MBOX2_BOOT_LOADING;
-        while ((bootresponse == MBOX2_BOOT_LOADING) && (count < 10)) {
+        bootresponse[0] = MBOX2_BOOT_LOADING;
+        while ((bootresponse[0] == MBOX2_BOOT_LOADING) && (count < 10)) {
                 msleep(500); /* 0.5 second delay */
                 snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0),
                         /* Control magic - load onboard firmware */
                         0x85, 0xc0, 0x0001, 0x0000, &bootresponse, 0x0012);
-                if (bootresponse == MBOX2_BOOT_READY)
+                if (bootresponse[0] == MBOX2_BOOT_READY)
                         break;
                 snd_printd("usb-audio: device not ready, resending boot sequence...\n");
                 count++;
         }
 
-        if (bootresponse != MBOX2_BOOT_READY) {
-                snd_printk(KERN_ERR "usb-audio: Unknown bootresponse=%d, or timed out, ignoring device.\n", bootresponse);
+        if (bootresponse[0] != MBOX2_BOOT_READY) {
+                snd_printk(KERN_ERR "usb-audio: Unknown bootresponse=%d, or timed out, ignoring device.\n", bootresponse[0]);
                 return -ENODEV;
         }
 
@@ -660,7 +659,6 @@ static int audiophile_skip_setting_quirk(struct snd_usb_audio *chip,
         return 0; /* keep this altsetting */
 }
 
-
 static int fasttrackpro_skip_setting_quirk(struct snd_usb_audio *chip,
                                            int iface, int altno)
 {
diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h
index a8172c119796..1ac3fd9cc5a6 100644
--- a/sound/usb/usbaudio.h
+++ b/sound/usb/usbaudio.h
@@ -76,7 +76,6 @@ enum quirk_type {
         QUIRK_MIDI_YAMAHA,
         QUIRK_MIDI_MIDIMAN,
         QUIRK_MIDI_NOVATION,
-        QUIRK_MIDI_MBOX2,
         QUIRK_MIDI_RAW_BYTES,
         QUIRK_MIDI_EMAGIC,
         QUIRK_MIDI_CME,