According to USB2.0 spec 8.5.3.3, for Control Read transfer, it should prime status stage as soon as prime data stage, as the data complete irq may never occur if the situation of ch8.5.3.3 happens. Delete below code at fsl_ep_queue: /* Update ep0 state */ if ((ep_index(ep) == 0)) udc->ep0_state = DATA_STATE_XMIT; the udc->ep0_state will be updated again after udc->driver->setup finishes. It is tested at i.mx51 bbg board with g_mass_storage, g_ether, g_serial. Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx> --- drivers/usb/gadget/fsl_udc_core.c | 23 +++++++++++++++-------- 1 files changed, 15 insertions(+), 8 deletions(-) diff --git a/drivers/usb/gadget/fsl_udc_core.c b/drivers/usb/gadget/fsl_udc_core.c index 34efcad..23cf6c1 100644 --- a/drivers/usb/gadget/fsl_udc_core.c +++ b/drivers/usb/gadget/fsl_udc_core.c @@ -920,10 +920,6 @@ fsl_ep_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags) return -ENOMEM; } - /* Update ep0 state */ - if ((ep_index(ep) == 0)) - udc->ep0_state = DATA_STATE_XMIT; - /* irq handler advances the queue */ if (req != NULL) list_add_tail(&req->queue, &ep->queue); @@ -1281,7 +1277,8 @@ static int ep0_prime_status(struct fsl_udc *udc, int direction) udc->ep0_dir = USB_DIR_OUT; ep = &udc->eps[0]; - udc->ep0_state = WAIT_FOR_OUT_STATUS; + if (udc->ep0_state != DATA_STATE_XMIT) + udc->ep0_state = WAIT_FOR_OUT_STATUS; req->ep = ep; req->req.length = 0; @@ -1386,6 +1383,9 @@ static void ch9getstatus(struct fsl_udc *udc, u8 request_type, u16 value, list_add_tail(&req->queue, &ep->queue); udc->ep0_state = DATA_STATE_XMIT; + if (ep0_prime_status(udc, EP_DIR_OUT)) + ep0stall(udc); + return; stall: ep0stall(udc); @@ -1494,6 +1494,14 @@ static void setup_received_irq(struct fsl_udc *udc, spin_lock(&udc->lock); udc->ep0_state = (setup->bRequestType & USB_DIR_IN) ? DATA_STATE_XMIT : DATA_STATE_RECV; + /* + * If the data stage is IN, send status prime immediately. + * See 2.0 Spec ch 8.5.3.3 for detail. + */ + if (udc->ep0_state == DATA_STATE_XMIT) + if (ep0_prime_status(udc, EP_DIR_OUT)) + ep0stall(udc); + } else { /* No data phase, IN status from gadget */ udc->ep0_dir = USB_DIR_IN; @@ -1522,9 +1530,8 @@ static void ep0_req_complete(struct fsl_udc *udc, struct fsl_ep *ep0, switch (udc->ep0_state) { case DATA_STATE_XMIT: - /* receive status phase */ - if (ep0_prime_status(udc, EP_DIR_OUT)) - ep0stall(udc); + /* already primed at setup_received_irq */ + udc->ep0_state = WAIT_FOR_OUT_STATUS; break; case DATA_STATE_RECV: /* send status phase */ -- 1.7.0.4 -- 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