usb: dwc3: ep0: preparation for handling non maxpacket aligned transfers > 512

No functional change. This is in preparation for handling non maxpacket
aligned transfers greater than bounce buffer size. This is basically to
avoid code duplication when using chained TRB transfers to handle
non maxpacket aligned transfers greater than bounce buffer size.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index 672d55a..396c2af 100644 (file)
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -783,7 +783,11 @@ static void dwc3_ep0_complete_data(struct dwc3 *dwc,
        struct usb_request      *ur;
        struct dwc3_trb         *trb;
        struct dwc3_ep          *ep0;
-       u32                     transferred;
+       unsigned                transfer_size = 0;
+       unsigned                maxp;
+       unsigned                remaining_ur_length;
+       void                    *buf;
+       u32                     transferred = 0;
        u32                     status;
        u32                     length;
        u8                      epnum;
@@ -812,20 +816,24 @@ static void dwc3_ep0_complete_data(struct dwc3 *dwc,
        }
 
        ur = &r->request;
+       buf = ur->buf;
+       remaining_ur_length = ur->length;
 
        length = trb->size & DWC3_TRB_SIZE_MASK;
 
+       maxp = ep0->endpoint.maxpacket;
+
        if (dwc->ep0_bounced) {
-               unsigned maxp = ep0->endpoint.maxpacket;
-               unsigned transfer_size = roundup(ur->length, maxp);
+               transfer_size = roundup((ur->length - transfer_size),
+                                       maxp);
 
                /* Maximum of DWC3_EP0_BOUNCE_SIZE can only be received */
                if (transfer_size > DWC3_EP0_BOUNCE_SIZE)
                        transfer_size = DWC3_EP0_BOUNCE_SIZE;
 
-               transferred = min_t(u32, ur->length,
-                               transfer_size - length);
-               memcpy(ur->buf, dwc->ep0_bounce, transferred);
+               transferred = min_t(u32, remaining_ur_length,
+                                   transfer_size - length);
+               memcpy(buf, dwc->ep0_bounce, transferred);
        } else {
                transferred = ur->length - length;
        }
@@ -934,7 +942,7 @@ static void __dwc3_ep0_do_control_data(struct dwc3 *dwc,
                                DWC3_TRBCTL_CONTROL_DATA);
        } else if (!IS_ALIGNED(req->request.length, dep->endpoint.maxpacket)
                        && (dep->number == 0)) {
-               u32     transfer_size;
+               u32     transfer_size = 0;
                u32     maxpacket;
 
                ret = usb_gadget_map_request(&dwc->gadget, &req->request,
@@ -945,7 +953,8 @@ static void __dwc3_ep0_do_control_data(struct dwc3 *dwc,
                }
 
                maxpacket = dep->endpoint.maxpacket;
-               transfer_size = roundup(req->request.length, maxpacket);
+               transfer_size = roundup((req->request.length - transfer_size),
+                                       maxpacket);
 
                if (transfer_size > DWC3_EP0_BOUNCE_SIZE) {
                        dev_WARN(dwc->dev, "bounce buf can't handle req len\n");