pstall
struct usb_fs_clear_stall_sync *pstall;
if (u.pstall->ep_index >= f->fs_ep_max) {
if (f->fs_xfer[u.pstall->ep_index] == NULL) {
error = usbd_transfer_pending(f->fs_xfer[u.pstall->ep_index]);
ep = f->fs_xfer[u.pstall->ep_index]->endpoint;
do { if ((p)->p_lock > (n)) pstall((p), (msg), (n)); } while (0)
void pstall (struct proc *, const char *, int);