char __user *buf, size_t len, int read)
{
struct ffs_epfile *epfile = file->private_data;
+ struct usb_gadget *gadget = epfile->ffs->gadget;
struct ffs_ep *ep;
char *data = NULL;
- ssize_t ret;
+ ssize_t ret, data_len;
int halt;
- goto first_try;
- do {
- spin_unlock_irq(&epfile->ffs->eps_lock);
- mutex_unlock(&epfile->mutex);
+ /* Are we still active? */
+ if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) {
+ ret = -ENODEV;
+ goto error;
+ }
-first_try:
- /* Are we still active? */
- if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) {
- ret = -ENODEV;
+ /* Wait for endpoint to be enabled */
+ ep = epfile->ep;
+ if (!ep) {
+ if (file->f_flags & O_NONBLOCK) {
+ ret = -EAGAIN;
goto error;
}
- /* Wait for endpoint to be enabled */
- ep = epfile->ep;
- if (!ep) {
- if (file->f_flags & O_NONBLOCK) {
- ret = -EAGAIN;
- goto error;
- }
-
- if (wait_event_interruptible(epfile->wait,
- (ep = epfile->ep))) {
- ret = -EINTR;
- goto error;
- }
- }
-
- /* Do we halt? */
- halt = !read == !epfile->in;
- if (halt && epfile->isoc) {
- ret = -EINVAL;
+ ret = wait_event_interruptible(epfile->wait, (ep = epfile->ep));
+ if (ret) {
+ ret = -EINTR;
goto error;
}
+ }
- /* Allocate & copy */
- if (!halt && !data) {
- data = kzalloc(len, GFP_KERNEL);
- if (unlikely(!data))
- return -ENOMEM;
+ /* Do we halt? */
+ halt = !read == !epfile->in;
+ if (halt && epfile->isoc) {
+ ret = -EINVAL;
+ goto error;
+ }
- if (!read &&
- unlikely(__copy_from_user(data, buf, len))) {
- ret = -EFAULT;
- goto error;
- }
- }
+ /* Allocate & copy */
+ if (!halt) {
+ /*
+ * Controller may require buffer size to be aligned to
+ * maxpacketsize of an out endpoint.
+ */
+ data_len = read ? usb_ep_align_maybe(gadget, ep->ep, len) : len;
+
+ data = kmalloc(data_len, GFP_KERNEL);
+ if (unlikely(!data))
+ return -ENOMEM;
- /* We will be using request */
- ret = ffs_mutex_lock(&epfile->mutex,
- file->f_flags & O_NONBLOCK);
- if (unlikely(ret))
+ if (!read && unlikely(copy_from_user(data, buf, len))) {
+ ret = -EFAULT;
goto error;
+ }
+ }
- /*
- * We're called from user space, we can use _irq rather then
- * _irqsave
- */
- spin_lock_irq(&epfile->ffs->eps_lock);
+ /* We will be using request */
+ ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK);
+ if (unlikely(ret))
+ goto error;
- /*
- * While we were acquiring mutex endpoint got disabled
- * or changed?
- */
- } while (unlikely(epfile->ep != ep));
+ spin_lock_irq(&epfile->ffs->eps_lock);
- /* Halt */
- if (unlikely(halt)) {
+ if (epfile->ep != ep) {
+ /* In the meantime, endpoint got disabled or changed. */
+ ret = -ESHUTDOWN;
+ spin_unlock_irq(&epfile->ffs->eps_lock);
+ } else if (halt) {
+ /* Halt */
if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
usb_ep_set_halt(ep->ep);
spin_unlock_irq(&epfile->ffs->eps_lock);
req->context = &done;
req->complete = ffs_epfile_io_complete;
req->buf = data;
- req->length = len;
+ req->length = data_len;
ret = usb_ep_queue(ep->ep, req, GFP_ATOMIC);
ret = -EINTR;
usb_ep_dequeue(ep->ep, req);
} else {
+ /*
+ * XXX We may end up silently droping data here.
+ * Since data_len (i.e. req->length) may be bigger
+ * than len (after being rounded up to maxpacketsize),
+ * we may end up with more data then user space has
+ * space for.
+ */
ret = ep->status;
if (read && ret > 0 &&
- unlikely(copy_to_user(buf, data, ret)))
+ unlikely(copy_to_user(buf, data,
+ min_t(size_t, ret, len))))
ret = -EFAULT;
}
}