ALSA: caiaq - Fix Oops with MIDI

The snd-usb-caiaq driver causes Oops occasionally when accessing MIDI
devices.  This patch fixes the Oops and invalid URB submission errors
as well.

Cc: stable@kernel.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>

2 files changed, 19 insertions, 14 deletions

diff --git a/sound/usb/caiaq/caiaq-device.h b/sound/usb/caiaq/caiaq-device.h
index f9fbdbae269d..ab56e738c5fc 100644
--- a/sound/usb/caiaq/caiaq-device.h
+++ b/sound/usb/caiaq/caiaq-device.h
@@ -75,6 +75,7 @@ struct snd_usb_caiaqdev {
         wait_queue_head_t ep1_wait_queue;
         wait_queue_head_t prepare_wait_queue;
         int spec_received, audio_parm_answer;
+        int midi_out_active;
 
         char vendor_name[CAIAQ_USB_STR_LEN];
         char product_name[CAIAQ_USB_STR_LEN];
diff --git a/sound/usb/caiaq/caiaq-midi.c b/sound/usb/caiaq/caiaq-midi.c
index 30b57f97c6e4..f19fd360c936 100644
--- a/sound/usb/caiaq/caiaq-midi.c
+++ b/sound/usb/caiaq/caiaq-midi.c
@@ -59,6 +59,11 @@ static int snd_usb_caiaq_midi_output_open(struct snd_rawmidi_substream *substrea
 
 static int snd_usb_caiaq_midi_output_close(struct snd_rawmidi_substream *substream)
 {
+        struct snd_usb_caiaqdev *dev = substream->rmidi->private_data;
+        if (dev->midi_out_active) {
+                usb_kill_urb(&dev->midi_out_urb);
+                dev->midi_out_active = 0;
+        }
         return 0;
 }
 
@@ -69,7 +74,8 @@ static void snd_usb_caiaq_midi_send(struct snd_usb_caiaqdev *dev,
         
         dev->midi_out_buf[0] = EP1_CMD_MIDI_WRITE;
         dev->midi_out_buf[1] = 0; /* port */
-        len = snd_rawmidi_transmit_peek(substream, dev->midi_out_buf+3, EP1_BUFSIZE-3);
+        len = snd_rawmidi_transmit(substream, dev->midi_out_buf + 3,
+                                   EP1_BUFSIZE - 3);
         
         if (len <= 0)
                 return;
@@ -79,24 +85,24 @@ static void snd_usb_caiaq_midi_send(struct snd_usb_caiaqdev *dev,
         
         ret = usb_submit_urb(&dev->midi_out_urb, GFP_ATOMIC);
         if (ret < 0)
-                log("snd_usb_caiaq_midi_send(%p): usb_submit_urb() failed, %d\n",
-                                substream, ret);
+                log("snd_usb_caiaq_midi_send(%p): usb_submit_urb() failed,"
+                    "ret=%d, len=%d\n",
+                    substream, ret, len);
+        else
+                dev->midi_out_active = 1;
 }
 
 static void snd_usb_caiaq_midi_output_trigger(struct snd_rawmidi_substream *substream, int up)
 {
         struct snd_usb_caiaqdev *dev = substream->rmidi->private_data;
         
-        if (dev->midi_out_substream != NULL)
-                return;
-        
-        if (!up) {
+        if (up) {
+                dev->midi_out_substream = substream;
+                if (!dev->midi_out_active)
+                        snd_usb_caiaq_midi_send(dev, substream);
+        } else {
                 dev->midi_out_substream = NULL;
-                return;
         }
-        
-        dev->midi_out_substream = substream;
-        snd_usb_caiaq_midi_send(dev, substream);
 }
 
 
@@ -161,16 +167,14 @@ int snd_usb_caiaq_midi_init(struct snd_usb_caiaqdev *device)
 void snd_usb_caiaq_midi_output_done(struct urb* urb)
 {
         struct snd_usb_caiaqdev *dev = urb->context;
-        char *buf = urb->transfer_buffer;
         
+        dev->midi_out_active = 0;
         if (urb->status != 0)
                 return;
 
         if (!dev->midi_out_substream)
                 return;
 
-        snd_rawmidi_transmit_ack(dev->midi_out_substream, buf[2]);
-        dev->midi_out_substream = NULL;
         snd_usb_caiaq_midi_send(dev, dev->midi_out_substream);
 }