USB: gadget: f_mtp: Add support for queueing multiple interrupt requests

Fixes problem sending "store added" events when there are multiple stores

Signed-off-by: Mike Lockwood <lockwood@android.com>

diff --git a/drivers/usb/gadget/f_mtp.c b/drivers/usb/gadget/f_mtp.c
index c892ec8154a71c0d610a770b7e7af14daec9a5c1..230dc8d788d95a8d55e7d3721524202cb57ef9f4 100644 (file)
--- a/drivers/usb/gadget/f_mtp.c
+++ b/drivers/usb/gadget/f_mtp.c
@@ -52,6 +52,7 @@
 /* number of tx and rx requests to allocate */
 #define TX_REQ_MAX 4
 #define RX_REQ_MAX 2
+#define INTR_REQ_MAX 5
 
 /* ID for Microsoft MTP OS String */
 #define MTP_OS_STRING_ID   0xEE
@@ -88,14 +89,13 @@ struct mtp_dev {
        atomic_t ioctl_excl;
 
        struct list_head tx_idle;
+       struct list_head intr_idle;
 
        wait_queue_head_t read_wq;
        wait_queue_head_t write_wq;
+       wait_queue_head_t intr_wq;
        struct usb_request *rx_req[RX_REQ_MAX];
-       struct usb_request *intr_req;
        int rx_done;
-       /* true if interrupt endpoint is busy */
-       int intr_busy;
 
        /* for processing MTP_SEND_FILE and MTP_RECEIVE_FILE
         * ioctls on a work queue
@@ -372,11 +372,12 @@ static void mtp_complete_intr(struct usb_ep *ep, struct usb_request *req)
 {
        struct mtp_dev *dev = _mtp_dev;
 
-       DBG(dev->cdev, "mtp_complete_intr status: %d actual: %d\n",
-               req->status, req->actual);
-       dev->intr_busy = 0;
        if (req->status != 0)
                dev->state = STATE_ERROR;
+
+       mtp_req_put(dev, &dev->intr_idle, req);
+
+       wake_up(&dev->intr_wq);
 }
 
 static int mtp_create_bulk_endpoints(struct mtp_dev *dev,
@@ -442,11 +443,13 @@ static int mtp_create_bulk_endpoints(struct mtp_dev *dev,
                req->complete = mtp_complete_out;
                dev->rx_req[i] = req;
        }
-       req = mtp_request_new(dev->ep_intr, INTR_BUFFER_SIZE);
-       if (!req)
-               goto fail;
-       req->complete = mtp_complete_intr;
-       dev->intr_req = req;
+       for (i = 0; i < INTR_REQ_MAX; i++) {
+               req = mtp_request_new(dev->ep_intr, INTR_BUFFER_SIZE);
+               if (!req)
+                       goto fail;
+               req->complete = mtp_complete_intr;
+               mtp_req_put(dev, &dev->intr_idle, req);
+       }
 
        return 0;
 
@@ -789,7 +792,7 @@ static void receive_file_work(struct work_struct *data)
 
 static int mtp_send_event(struct mtp_dev *dev, struct mtp_event *event)
 {
-       struct usb_request *req;
+       struct usb_request *req= NULL;
        int ret;
        int length = event->length;
 
@@ -799,21 +802,20 @@ static int mtp_send_event(struct mtp_dev *dev, struct mtp_event *event)
                return -EINVAL;
        if (dev->state == STATE_OFFLINE)
                return -ENODEV;
-       /* unfortunately an interrupt request might hang indefinitely if the host
-        * is not listening on the interrupt endpoint, so instead of waiting,
-        * we just fail if the endpoint is busy.
-        */
-       if (dev->intr_busy)
-               return -EBUSY;
 
-       req = dev->intr_req;
-       if (copy_from_user(req->buf, (void __user *)event->data, length))
+       ret = wait_event_interruptible_timeout(dev->intr_wq,
+               (req = mtp_req_get(dev, &dev->intr_idle)), msecs_to_jiffies(1000));
+       if (!req)
+           return -ETIME;
+
+       if (copy_from_user(req->buf, (void __user *)event->data, length)) {
+               mtp_req_put(dev, &dev->intr_idle, req);
                return -EFAULT;
+       }
        req->length = length;
-       dev->intr_busy = 1;
        ret = usb_ep_queue(dev->ep_intr, req, GFP_KERNEL);
        if (ret)
-               dev->intr_busy = 0;
+               mtp_req_put(dev, &dev->intr_idle, req);
 
        return ret;
 }
@@ -1050,7 +1052,8 @@ mtp_function_unbind(struct usb_configuration *c, struct usb_function *f)
                mtp_request_free(req, dev->ep_in);
        for (i = 0; i < RX_REQ_MAX; i++)
                mtp_request_free(dev->rx_req[i], dev->ep_out);
-       mtp_request_free(dev->intr_req, dev->ep_intr);
+       while ((req = mtp_req_get(dev, &dev->intr_idle)))
+               mtp_request_free(req, dev->ep_intr);
        dev->state = STATE_OFFLINE;
 }
 
@@ -1243,9 +1246,11 @@ static int mtp_setup(void)
        spin_lock_init(&dev->lock);
        init_waitqueue_head(&dev->read_wq);
        init_waitqueue_head(&dev->write_wq);
+       init_waitqueue_head(&dev->intr_wq);
        atomic_set(&dev->open_excl, 0);
        atomic_set(&dev->ioctl_excl, 0);
        INIT_LIST_HEAD(&dev->tx_idle);
+       INIT_LIST_HEAD(&dev->intr_idle);
 
        dev->wq = create_singlethread_workqueue("f_mtp");
        if (!dev->wq) {