usb: chipidea: udc: read status of td only once in hardware_dequeue

This patch changes the read of the td status to one atomic operation to
analyse coherent bits.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
[Alex: fixed backwards endianness conversion]
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
index 94af020..20a5b79 100644 (file)
--- a/drivers/usb/chipidea/udc.c
+++ b/drivers/usb/chipidea/udc.c
@@ -481,10 +481,12 @@ done:
  */
 static int _hardware_dequeue(struct ci13xxx_ep *mEp, struct ci13xxx_req *mReq)
 {
+       u32 tmptoken = le32_to_cpu(mReq->ptr->token);
+
        if (mReq->req.status != -EALREADY)
                return -EINVAL;
 
-       if ((cpu_to_le32(TD_STATUS_ACTIVE) & mReq->ptr->token) != 0)
+       if ((TD_STATUS_ACTIVE & tmptoken) != 0)
                return -EBUSY;
 
        if (mReq->zptr) {
@@ -498,7 +500,7 @@ static int _hardware_dequeue(struct ci13xxx_ep *mEp, struct ci13xxx_req *mReq)
 
        usb_gadget_unmap_request(&mEp->ci->gadget, &mReq->req, mEp->dir);
 
-       mReq->req.status = le32_to_cpu(mReq->ptr->token) & TD_STATUS;
+       mReq->req.status = tmptoken & TD_STATUS;
        if ((TD_STATUS_HALTED & mReq->req.status) != 0)
                mReq->req.status = -1;
        else if ((TD_STATUS_DT_ERR & mReq->req.status) != 0)
@@ -506,7 +508,7 @@ static int _hardware_dequeue(struct ci13xxx_ep *mEp, struct ci13xxx_req *mReq)
        else if ((TD_STATUS_TR_ERR & mReq->req.status) != 0)
                mReq->req.status = -1;
 
-       mReq->req.actual   = le32_to_cpu(mReq->ptr->token) & TD_TOTAL_BYTES;
+       mReq->req.actual   = tmptoken & TD_TOTAL_BYTES;
        mReq->req.actual >>= __ffs(TD_TOTAL_BYTES);
        mReq->req.actual   = mReq->req.length - mReq->req.actual;
        mReq->req.actual   = mReq->req.status ? 0 : mReq->req.actual;