xhci: handle failed buffer copy to URB sg list and fix a W=1 copiler warning

Set the urb->actual_length to bytes successfully copied in case all bytes
weren't copied from a temporary buffer to the URB sg list.
Also print a debug message

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210617150354.1512157-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 27283654ca08047a9fb0f50441101a4467485218..9248ce8d09a4a3489a61f4b4f2f87b8722bc8549 100644 (file)
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1361,12 +1361,17 @@ static void xhci_unmap_temp_buf(struct usb_hcd *hcd, struct urb *urb)
                                 urb->transfer_buffer_length,
                                 dir);
 
-       if (usb_urb_dir_in(urb))
+       if (usb_urb_dir_in(urb)) {
                len = sg_pcopy_from_buffer(urb->sg, urb->num_sgs,
                                           urb->transfer_buffer,
                                           buf_len,
                                           0);
-
+               if (len != buf_len) {
+                       xhci_dbg(hcd_to_xhci(hcd),
+                                "Copy from tmp buf to urb sg list failed\n");
+                       urb->actual_length = len;
+               }
+       }
        urb->transfer_flags &= ~URB_DMA_MAP_SINGLE;
        kfree(urb->transfer_buffer);
        urb->transfer_buffer = NULL;