Bluetooth: btusb: Separate TX URB allocation and submission

The complete TX URB handling is done via a switch statement in the
btusb_send_frame function. To allow for more clear separation between
control, bulk and isoc URBs, split them into allocation and submission.

Previously the inc_tx function has been used for tracking in-flight
URB for HCI commands and ACL data packets. Convert that into a common
function that either submits the URB or queues it when needed.

This provides the flexibility to allow vendor specific hdev->send_frame
callbacks without having to duplicate the whole URB handling logic.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

1 files changed, 125 insertions, 81 deletions

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index d696e68f326a..c89b330cfa9e 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -296,20 +296,6 @@ struct btusb_data {
         int suspend_count;
 };
 
-static int inc_tx(struct btusb_data *data)
-{
-        unsigned long flags;
-        int rv;
-
-        spin_lock_irqsave(&data->txlock, flags);
-        rv = test_bit(BTUSB_SUSPENDING, &data->flags);
-        if (!rv)
-                data->tx_in_flight++;
-        spin_unlock_irqrestore(&data->txlock, flags);
-
-        return rv;
-}
-
 static void btusb_intr_complete(struct urb *urb)
 {
         struct hci_dev *hdev = urb->context;
@@ -752,100 +738,96 @@ static int btusb_flush(struct hci_dev *hdev)
         return 0;
 }
 
-static int btusb_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
+static struct urb *alloc_ctrl_urb(struct hci_dev *hdev, struct sk_buff *skb)
 {
         struct btusb_data *data = hci_get_drvdata(hdev);
         struct usb_ctrlrequest *dr;
         struct urb *urb;
         unsigned int pipe;
-        int err;
 
-        BT_DBG("%s", hdev->name);
+        urb = usb_alloc_urb(0, GFP_KERNEL);
+        if (!urb)
+                return ERR_PTR(-ENOMEM);
 
-        if (!test_bit(HCI_RUNNING, &hdev->flags))
-                return -EBUSY;
+        dr = kmalloc(sizeof(*dr), GFP_KERNEL);
+        if (!dr) {
+                usb_free_urb(urb);
+                return ERR_PTR(-ENOMEM);
+        }
 
-        skb->dev = (void *) hdev;
+        dr->bRequestType = data->cmdreq_type;
+        dr->bRequest     = 0;
+        dr->wIndex       = 0;
+        dr->wValue       = 0;
+        dr->wLength      = __cpu_to_le16(skb->len);
 
-        switch (bt_cb(skb)->pkt_type) {
-        case HCI_COMMAND_PKT:
-                urb = usb_alloc_urb(0, GFP_KERNEL);
-                if (!urb)
-                        return -ENOMEM;
-
-                dr = kmalloc(sizeof(*dr), GFP_KERNEL);
-                if (!dr) {
-                        usb_free_urb(urb);
-                        return -ENOMEM;
-                }
+        pipe = usb_sndctrlpipe(data->udev, 0x00);
 
-                dr->bRequestType = data->cmdreq_type;
-                dr->bRequest     = 0;
-                dr->wIndex       = 0;
-                dr->wValue       = 0;
-                dr->wLength      = __cpu_to_le16(skb->len);
+        usb_fill_control_urb(urb, data->udev, pipe, (void *) dr,
+                             skb->data, skb->len, btusb_tx_complete, skb);
 
-                pipe = usb_sndctrlpipe(data->udev, 0x00);
+        skb->dev = (void *) hdev;
 
-                usb_fill_control_urb(urb, data->udev, pipe, (void *) dr,
-                                skb->data, skb->len, btusb_tx_complete, skb);
+        return urb;
+}
 
-                hdev->stat.cmd_tx++;
-                break;
+static struct urb *alloc_bulk_urb(struct hci_dev *hdev, struct sk_buff *skb)
+{
+        struct btusb_data *data = hci_get_drvdata(hdev);
+        struct urb *urb;
+        unsigned int pipe;
 
-        case HCI_ACLDATA_PKT:
-                if (!data->bulk_tx_ep)
-                        return -ENODEV;
+        if (!data->bulk_tx_ep)
+                return ERR_PTR(-ENODEV);
 
-                urb = usb_alloc_urb(0, GFP_KERNEL);
-                if (!urb)
-                        return -ENOMEM;
+        urb = usb_alloc_urb(0, GFP_KERNEL);
+        if (!urb)
+                return ERR_PTR(-ENOMEM);
 
-                pipe = usb_sndbulkpipe(data->udev,
-                                        data->bulk_tx_ep->bEndpointAddress);
+        pipe = usb_sndbulkpipe(data->udev, data->bulk_tx_ep->bEndpointAddress);
 
-                usb_fill_bulk_urb(urb, data->udev, pipe,
-                                skb->data, skb->len, btusb_tx_complete, skb);
+        usb_fill_bulk_urb(urb, data->udev, pipe,
+                          skb->data, skb->len, btusb_tx_complete, skb);
 
-                hdev->stat.acl_tx++;
-                break;
+        skb->dev = (void *) hdev;
 
-        case HCI_SCODATA_PKT:
-                if (!data->isoc_tx_ep || hci_conn_num(hdev, SCO_LINK) < 1)
-                        return -ENODEV;
+        return urb;
+}
 
-                urb = usb_alloc_urb(BTUSB_MAX_ISOC_FRAMES, GFP_KERNEL);
-                if (!urb)
-                        return -ENOMEM;
+static struct urb *alloc_isoc_urb(struct hci_dev *hdev, struct sk_buff *skb)
+{
+        struct btusb_data *data = hci_get_drvdata(hdev);
+        struct urb *urb;
+        unsigned int pipe;
 
-                pipe = usb_sndisocpipe(data->udev,
-                                        data->isoc_tx_ep->bEndpointAddress);
+        if (!data->isoc_tx_ep)
+                return ERR_PTR(-ENODEV);
 
-                usb_fill_int_urb(urb, data->udev, pipe,
-                                skb->data, skb->len, btusb_isoc_tx_complete,
-                                skb, data->isoc_tx_ep->bInterval);
+        urb = usb_alloc_urb(BTUSB_MAX_ISOC_FRAMES, GFP_KERNEL);
+        if (!urb)
+                return ERR_PTR(-ENOMEM);
 
-                urb->transfer_flags  = URB_ISO_ASAP;
+        pipe = usb_sndisocpipe(data->udev, data->isoc_tx_ep->bEndpointAddress);
 
-                __fill_isoc_descriptor(urb, skb->len,
-                                le16_to_cpu(data->isoc_tx_ep->wMaxPacketSize));
+        usb_fill_int_urb(urb, data->udev, pipe,
+                         skb->data, skb->len, btusb_isoc_tx_complete,
+                         skb, data->isoc_tx_ep->bInterval);
 
-                hdev->stat.sco_tx++;
-                goto skip_waking;
+        urb->transfer_flags  = URB_ISO_ASAP;
 
-        default:
-                return -EILSEQ;
-        }
+        __fill_isoc_descriptor(urb, skb->len,
+                               le16_to_cpu(data->isoc_tx_ep->wMaxPacketSize));
 
-        err = inc_tx(data);
-        if (err) {
-                usb_anchor_urb(urb, &data->deferred);
-                schedule_work(&data->waker);
-                err = 0;
-                goto done;
-        }
+        skb->dev = (void *) hdev;
+
+        return urb;
+}
+
+static int submit_tx_urb(struct hci_dev *hdev, struct urb *urb)
+{
+        struct btusb_data *data = hci_get_drvdata(hdev);
+        int err;
 
-skip_waking:
         usb_anchor_urb(urb, &data->tx_anchor);
 
         err = usb_submit_urb(urb, GFP_KERNEL);
@@ -859,11 +841,73 @@ skip_waking:
                 usb_mark_last_busy(data->udev);
         }
 
-done:
         usb_free_urb(urb);
         return err;
 }
 
+static int submit_or_queue_tx_urb(struct hci_dev *hdev, struct urb *urb)
+{
+        struct btusb_data *data = hci_get_drvdata(hdev);
+        unsigned long flags;
+        bool suspending;
+
+        spin_lock_irqsave(&data->txlock, flags);
+        suspending = test_bit(BTUSB_SUSPENDING, &data->flags);
+        if (!suspending)
+                data->tx_in_flight++;
+        spin_unlock_irqrestore(&data->txlock, flags);
+
+        if (!suspending)
+                return submit_tx_urb(hdev, urb);
+
+        usb_anchor_urb(urb, &data->deferred);
+        schedule_work(&data->waker);
+
+        usb_free_urb(urb);
+        return 0;
+}
+
+static int btusb_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
+{
+        struct urb *urb;
+
+        BT_DBG("%s", hdev->name);
+
+        if (!test_bit(HCI_RUNNING, &hdev->flags))
+                return -EBUSY;
+
+        switch (bt_cb(skb)->pkt_type) {
+        case HCI_COMMAND_PKT:
+                urb = alloc_ctrl_urb(hdev, skb);
+                if (IS_ERR(urb))
+                        return PTR_ERR(urb);
+
+                hdev->stat.cmd_tx++;
+                return submit_or_queue_tx_urb(hdev, urb);
+
+        case HCI_ACLDATA_PKT:
+                urb = alloc_bulk_urb(hdev, skb);
+                if (IS_ERR(urb))
+                        return PTR_ERR(urb);
+
+                hdev->stat.acl_tx++;
+                return submit_or_queue_tx_urb(hdev, urb);
+
+        case HCI_SCODATA_PKT:
+                if (hci_conn_num(hdev, SCO_LINK) < 1)
+                        return -ENODEV;
+
+                urb = alloc_isoc_urb(hdev, skb);
+                if (IS_ERR(urb))
+                        return PTR_ERR(urb);
+
+                hdev->stat.sco_tx++;
+                return submit_tx_urb(hdev, urb);
+        }
+
+        return -EILSEQ;
+}
+
 static void btusb_notify(struct hci_dev *hdev, unsigned int evt)
 {
         struct btusb_data *data = hci_get_drvdata(hdev);