[PATCH 6/6] net: dwc_eth_qos: Prevent DMA from writing updated RX DMA descriptor

[Patrick DELAUNAY]

Dear Marek,

> From: Marek Vasut <marex at denx.de>
> Sent: lundi 23 mars 2020 02:45
> 
> The DMA may attempt to write a DMA descriptor in the ring while it is being
> updated. By writing the DMA descriptor buffer address to 0, it is assured the DMA
> will not use such a buffer and the buffer can be updated without any interference.
> 
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Joe Hershberger <joe.hershberger at ni.com>
> Cc: Patrice Chotard <patrice.chotard at st.com>
> Cc: Patrick Delaunay <patrick.delaunay at st.com>
> Cc: Ramon Fried <rfried.dev at gmail.com>
> Cc: Stephen Warren <swarren at nvidia.com>
> ---

Reviewed-by: Patrick Delaunay <patrick.delaunay at st.com>