3 files changed, 38 insertions, 20 deletions

diff --git a/sound/firewire/dice/dice.c b/sound/firewire/dice/dice.c
index 53ca441ea9b9..96fe68f42e5d 100644
--- a/sound/firewire/dice/dice.c
+++ b/sound/firewire/dice/dice.c
@@ -20,8 +20,6 @@ MODULE_LICENSE("GPL v2");
 #define WEISS_CATEGORY_ID       0x00
 #define LOUD_CATEGORY_ID        0x10
 
-#define PROBE_DELAY_MS          (2 * MSEC_PER_SEC)
-
 /*
  * Some models support several isochronous channels, while these streams are not
  * always available. In this case, add the model name to this list.
@@ -235,27 +233,12 @@ static void do_registration(struct work_struct *work)
 error:
         snd_dice_stream_destroy_duplex(dice);
         snd_dice_transaction_destroy(dice);
+        snd_dice_stream_destroy_duplex(dice);
         snd_card_free(dice->card);
         dev_info(&dice->unit->device,
                  "Sound card registration failed: %d\n", err);
 }
 
-static void schedule_registration(struct snd_dice *dice)
-{
-        struct fw_card *fw_card = fw_parent_device(dice->unit)->card;
-        u64 now, delay;
-
-        now = get_jiffies_64();
-        delay = fw_card->reset_jiffies + msecs_to_jiffies(PROBE_DELAY_MS);
-
-        if (time_after64(delay, now))
-                delay -= now;
-        else
-                delay = 0;
-
-        mod_delayed_work(system_wq, &dice->dwork, delay);
-}
-
 static int dice_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
 {
         struct snd_dice *dice;
@@ -280,7 +263,7 @@ static int dice_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
 
         /* Allocate and register this sound card later. */
         INIT_DEFERRABLE_WORK(&dice->dwork, do_registration);
-        schedule_registration(dice);
+        snd_fw_schedule_registration(unit, &dice->dwork);
 
         return 0;
 }
@@ -311,7 +294,7 @@ static void dice_bus_reset(struct fw_unit *unit)
 
         /* Postpone a workqueue for deferred registration. */
         if (!dice->registered)
-                schedule_registration(dice);
+                snd_fw_schedule_registration(unit, &dice->dwork);
 
         /* The handler address register becomes initialized. */
         snd_dice_transaction_reinit(dice);
diff --git a/sound/firewire/lib.c b/sound/firewire/lib.c
index f80aafa44c89..ca4dfcf43175 100644
--- a/sound/firewire/lib.c
+++ b/sound/firewire/lib.c
@@ -67,6 +67,38 @@ int snd_fw_transaction(struct fw_unit *unit, int tcode,
 }
 EXPORT_SYMBOL(snd_fw_transaction);
 
+#define PROBE_DELAY_MS          (2 * MSEC_PER_SEC)
+
+/**
+ * snd_fw_schedule_registration - schedule work for sound card registration
+ * @unit: an instance for unit on IEEE 1394 bus
+ * @dwork: delayed work with callback function
+ *
+ * This function is not designed for general purposes. When new unit is
+ * connected to IEEE 1394 bus, the bus is under bus-reset state because of
+ * topological change. In this state, units tend to fail both of asynchronous
+ * and isochronous communication. To avoid this problem, this function is used
+ * to postpone sound card registration after the state. The callers must
+ * set up instance of delayed work in advance.
+ */
+void snd_fw_schedule_registration(struct fw_unit *unit,
+                                  struct delayed_work *dwork)
+{
+        u64 now, delay;
+
+        now = get_jiffies_64();
+        delay = fw_parent_device(unit)->card->reset_jiffies
+                                        + msecs_to_jiffies(PROBE_DELAY_MS);
+
+        if (time_after64(delay, now))
+                delay -= now;
+        else
+                delay = 0;
+
+        mod_delayed_work(system_wq, dwork, delay);
+}
+EXPORT_SYMBOL(snd_fw_schedule_registration);
+
 static void async_midi_port_callback(struct fw_card *card, int rcode,
                                      void *data, size_t length,
                                      void *callback_data)
diff --git a/sound/firewire/lib.h b/sound/firewire/lib.h
index f3f6f84c48d6..f6769312ebfc 100644
--- a/sound/firewire/lib.h
+++ b/sound/firewire/lib.h
@@ -22,6 +22,9 @@ static inline bool rcode_is_permanent_error(int rcode)
         return rcode == RCODE_TYPE_ERROR || rcode == RCODE_ADDRESS_ERROR;
 }
 
+void snd_fw_schedule_registration(struct fw_unit *unit,
+                                  struct delayed_work *dwork);
+
 struct snd_fw_async_midi_port;
 typedef int (*snd_fw_async_midi_port_fill)(
                                 struct snd_rawmidi_substream *substream,