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    SubjectRe: drivers/block/ub.c
    Date
    Am Samstag, 26. Juni 2004 23:41 schrieb David S. Miller:
    > On Sat, 26 Jun 2004 22:35:15 +0200
    > Oliver Neukum <oliver@neukum.org> wrote:
    >
    > >
    > > > +/* command block wrapper */
    > > > +struct bulk_cb_wrap {
    > > > + u32 Signature; /* contains 'USBC' */
    > > > + u32 Tag; /* unique per command id */
    > > > + u32 DataTransferLength; /* size of data */
    > > > + u8 Flags; /* direction in bit 0 */
    > > > + u8 Lun; /* LUN normally 0 */
    > > > + u8 Length; /* of of the CDB */
    > > > + u8 CDB[MAX_CDB_SIZE]; /* max command */
    > > > +};
    > >
    > > should be packed attributed
    >
    > Only when necessary, and I do not belive any platform Linux supports
    > needs it in this case.
    >
    > Packed attributing is _BAD_ when it isn't needed because it forces GCC
    > to output multiple byte-sized loads in order to access larger than
    > byte-sized elements because it cannot assume the proper alignment on RISC
    > systems.

    Unless I am mistaken, this structure is transfered as such over the bus,
    so IMHO here it is needed.

    Regards
    Oliver
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