usbdevfs: Fix broken scatter-gather transfer

commit 014639003c77a51fc319c9fdf225e7747cb6e18d upstream.

The handling of large output bulk transfers is broken; the same user
page is read over and over again. Fixed with this patch.

Acked-by: Peter Stuge <peter@stuge.se>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index ebb8a9de8b5fe448c98e0c25ec394e68c784d5b5..7f75343a15ba2d84a56ad8e8930ccee02d2ebf08 100644 (file)
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -1348,6 +1348,7 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
                                        ret = -EFAULT;
                                        goto error;
                                }
+                               uurb->buffer += u;
                        }
                        totlen -= u;
                }