[PATCH] gianfar: Add I/O barriers when touching buffer descriptor ownership.

[Jeff Garzik]

Scott Wood wrote:
> The hardware must not see that is given ownership of a buffer until it is
> completely written, and when the driver receives ownership of a buffer,
> it must ensure that any other reads to the buffer reflect its final
> state.  Thus, I/O barriers are added where required.
> 
> Without this patch, I have observed GCC reordering the setting of
> bdp->length and bdp->status in gfar_new_skb.  Hardware reordering
> was also theoretically possible.
> 
> Signed-off-by: Scott Wood <scottwood at freescale.com>
> ---
> I've added the requested comments to the source code about
> the use of eieio().  Jeff, please consider for 2.6.22, as it
> fixes a bug that has been observed.
> 
>  drivers/net/gianfar.c |   11 +++++++++++
>  1 files changed, 11 insertions(+), 0 deletions(-)

applied