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    SubjectRe: [PATCH v12 4/8] usb:gadget: Add SuperSpeed support to the Gadget Framework
    On Tue, May 24, 2011 at 01:10, Tanya Brokhman wrote:
    >> >+    case USB_REQ_GET_STATUS:
    >> >+            if (!gadget_is_superspeed(gadget))
    >> >+                    goto unknown;
    >> >+            if (ctrl->bRequestType != (USB_DIR_IN | USB_RECIP_INTERFACE))
    >> >+                    goto unknown;
    >> >+            value = 2;      /* This is the length of the get_status
    >> >+            *((__le16 *)req->buf) = 0;
    >>
    >> Mike please correct me if I'm wrong bug this looks like a case for
    >> put_unaligned_le16().
    >> Is someone actually using gadget support on blackfin? I'm asking
    >> because
    >> config_buf() (same file, upstream) is using req->buf to build the
    >> descriptors in place and one element is le16 which should be affected.
    >
    > Mike answered that you're right in your observation. I'm not familiar with
    > blackfin. Could you please elaborate on this? I understand that I need to
    > use put_unaligned_le16(), will do, but I would like to better understand why
    > and if there is a way to test this so that blackfin won't be broken.

    not all arches support unaligned accesses. or they do, but it's done
    via (non-trivial) exception processing in software. req->buf is of
    type void* and so presumably is not guaranteed to be aligned on a 2
    byte boundary.
    -mike
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