usb: gadget: mv_udc: fix bug in ep_dequeue

According to ChipIdea's SPEC, we cannot touch curr_dtd_ptr in dqh
directly, use prime endpoint instead.

Signed-off-by: Neil Zhang <zhangwm@marvell.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/gadget/mv_udc_core.c b/drivers/usb/gadget/mv_udc_core.c
index 0ad321d..a3a7664 100644 (file)
--- a/drivers/usb/gadget/mv_udc_core.c
+++ b/drivers/usb/gadget/mv_udc_core.c
@@ -778,6 +778,27 @@ mv_ep_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
        return 0;
 }
 
+static void mv_prime_ep(struct mv_ep *ep, struct mv_req *req)
+{
+       struct mv_dqh *dqh = ep->dqh;
+       u32 bit_pos;
+
+       /* Write dQH next pointer and terminate bit to 0 */
+       dqh->next_dtd_ptr = req->head->td_dma
+               & EP_QUEUE_HEAD_NEXT_POINTER_MASK;
+
+       /* clear active and halt bit, in case set from a previous error */
+       dqh->size_ioc_int_sts &= ~(DTD_STATUS_ACTIVE | DTD_STATUS_HALTED);
+
+       /* Ensure that updates to the QH will occure before priming. */
+       wmb();
+
+       bit_pos = 1 << (((ep_dir(ep) == EP_DIR_OUT) ? 0 : 16) + ep->ep_num);
+
+       /* Prime the Endpoint */
+       writel(bit_pos, &ep->udc->op_regs->epprime);
+}
+
 /* dequeues (cancels, unlinks) an I/O request from an endpoint */
 static int mv_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
 {
@@ -820,15 +841,13 @@ static int mv_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
 
                /* The request isn't the last request in this ep queue */
                if (req->queue.next != &ep->queue) {
-                       struct mv_dqh *qh;
                        struct mv_req *next_req;
 
-                       qh = ep->dqh;
-                       next_req = list_entry(req->queue.next, struct mv_req,
-                                       queue);
+                       next_req = list_entry(req->queue.next,
+                               struct mv_req, queue);
 
                        /* Point the QH to the first TD of next request */
-                       writel((u32) next_req->head, &qh->curr_dtd_ptr);
+                       mv_prime_ep(ep, next_req);
                } else {
                        struct mv_dqh *qh;