usb: cdns3: gadget: clear trb->length as zero after preparing every trb

It clears trb->length as zero before preparing td, but if scatter
buffer is used for td, there are several trbs within td, it needs to clear
every trb->length as zero, otherwise, the default value for trb->length
may not be zero after it begins to use the second round of trb rings.

Fixes: abc6b579048e ("usb: cdns3: gadget: using correct sg operations")
Signed-off-by: Peter Chen <peter.chen@nxp.com>

diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
index 365f30fb115994c4de6be23d0eb0e3c9ec6845fd..0aa85cc07ff19e48f3a914c4639e16ac145f7be7 100644 (file)
--- a/drivers/usb/cdns3/gadget.c
+++ b/drivers/usb/cdns3/gadget.c
@@ -1260,6 +1260,7 @@ static int cdns3_ep_run_transfer(struct cdns3_endpoint *priv_ep,
                priv_req->end_trb = priv_ep->enqueue;
                cdns3_ep_inc_enq(priv_ep);
                trb = priv_ep->trb_pool + priv_ep->enqueue;
+               trb->length = 0;
        } while (sg_iter < num_trb);
 
        trb = priv_req->trb;