From: Alexander Sverdlin alexander.sverdlin@nokia.com
commit 0c34bb598c510e070160029f34efeeb217000f8d upstream.
The removal of mips_swiotlb_ops exposed a problem in octeon_mgmt Ethernet driver. mips_swiotlb_ops had an mb() after most of the operations and the removal of the ops had broken the receive functionality of the driver. My code inspection has shown no other places except octeon_mgmt_rx_fill_ring() where an explicit barrier would be obviously missing. The latter function however has to make sure that "ringing the bell" doesn't happen before RX ring entry is really written.
The patch has been successfully tested on Octeon II.
Fixes: a999933db9ed ("MIPS: remove mips_swiotlb_ops") Cc: stable@vger.kernel.org Signed-off-by: Alexander Sverdlin alexander.sverdlin@nokia.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/net/ethernet/cavium/octeon/octeon_mgmt.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/drivers/net/ethernet/cavium/octeon/octeon_mgmt.c +++ b/drivers/net/ethernet/cavium/octeon/octeon_mgmt.c @@ -234,6 +234,11 @@ static void octeon_mgmt_rx_fill_ring(str
/* Put it in the ring. */ p->rx_ring[p->rx_next_fill] = re.d64; + /* Make sure there is no reorder of filling the ring and ringing + * the bell + */ + wmb(); + dma_sync_single_for_device(p->dev, p->rx_ring_handle, ring_size_to_bytes(OCTEON_MGMT_RX_RING_SIZE), DMA_BIDIRECTIONAL);