In working on a project (http://github.com/dominicgs/USBProxy) we ran across an issue where io on endpoint 0 would cause the system to hang. We made the following change which resolved the problem for us. I'm not sure if this is the "correct" fix, or if the problem is specific to our platform BeagleBone Black with a musb-hrdc controller. --- inode.c 2013-11-18 14:46:25.255029000 -0500 +++ inode.c2 2013-11-19 06:30:36.579029000 -0500 @@ -679,7 +679,9 @@ req->length = len; req->complete = ep_aio_complete; req->context = iocb; + spin_unlock_irq(&epdata->dev->lock); value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC); + spin_lock_irq(&epdata->dev->lock); if (unlikely(0 != value)) usb_ep_free_request(epdata->ep, req); } else @@ -1012,8 +1014,11 @@ struct usb_ep *ep = dev->gadget->ep0; struct usb_request *req = dev->req; - if ((retval = setup_req (ep, req, 0)) == 0) + if ((retval = setup_req (ep, req, 0)) == 0) { + spin_unlock_irq (&dev->lock); retval = usb_ep_queue (ep, req, GFP_ATOMIC); + spin_lock_irq (&dev->lock); + } dev->state = STATE_DEV_CONNECTED; /* assume that was SET_CONFIGURATION */ -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
