2 files changed, 18 insertions, 1 deletions

diff --git a/sound/firewire/lib.c b/sound/firewire/lib.c
index 3e9afd7d402c..9a98c7cd8744 100644
--- a/sound/firewire/lib.c
+++ b/sound/firewire/lib.c
@@ -76,6 +76,9 @@ static void async_midi_port_callback(struct fw_card *card, int rcode,
 
         if (rcode == RCODE_COMPLETE && substream != NULL)
                 snd_rawmidi_transmit_ack(substream, port->consume_bytes);
+        else if (!rcode_is_permanent_error(rcode))
+                /* To start next transaction immediately for recovery. */
+                port->next_ktime = ktime_set(0, 0);
 
         port->idling = true;
 
@@ -99,6 +102,12 @@ static void midi_port_work(struct work_struct *work)
         if (substream == NULL || snd_rawmidi_transmit_empty(substream))
                 return;
 
+        /* Do it in next chance. */
+        if (ktime_after(port->next_ktime, ktime_get())) {
+                schedule_work(&port->work);
+                return;
+        }
+
         /*
          * Fill the buffer. The callee must use snd_rawmidi_transmit_peek().
          * Later, snd_rawmidi_transmit_ack() is called.
@@ -107,8 +116,10 @@ static void midi_port_work(struct work_struct *work)
         port->consume_bytes = port->fill(substream, port->buf);
         if (port->consume_bytes <= 0) {
                 /* Do it in next chance, immediately. */
-                if (port->consume_bytes == 0)
+                if (port->consume_bytes == 0) {
+                        port->next_ktime = ktime_set(0, 0);
                         schedule_work(&port->work);
+                }
                 return;
         }
 
@@ -118,6 +129,10 @@ static void midi_port_work(struct work_struct *work)
         else
                 type = TCODE_WRITE_BLOCK_REQUEST;
 
+        /* Set interval to next transaction. */
+        port->next_ktime = ktime_add_ns(ktime_get(),
+                                port->consume_bytes * 8 * NSEC_PER_SEC / 31250);
+
         /* Start this transaction. */
         port->idling = false;
 
@@ -162,6 +177,7 @@ int snd_fw_async_midi_port_init(struct snd_fw_async_midi_port *port,
         port->addr = addr;
         port->fill = fill;
         port->idling = true;
+        port->next_ktime = ktime_set(0, 0);
 
         INIT_WORK(&port->work, midi_port_work);
 
diff --git a/sound/firewire/lib.h b/sound/firewire/lib.h
index 0af06f44e8c2..59e086587212 100644
--- a/sound/firewire/lib.h
+++ b/sound/firewire/lib.h
@@ -31,6 +31,7 @@ struct snd_fw_async_midi_port {
         struct fw_device *parent;
         struct work_struct work;
         bool idling;
+        ktime_t next_ktime;
 
         u64 addr;
         struct fw_transaction transaction;