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 <[email protected]> Cc: Joe Hershberger <[email protected]> Cc: Patrice Chotard <[email protected]> Cc: Patrick Delaunay <[email protected]> Cc: Ramon Fried <[email protected]> Cc: Stephen Warren <[email protected]> --- drivers/net/dwc_eth_qos.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/dwc_eth_qos.c b/drivers/net/dwc_eth_qos.c index 7dadb10fe7..c86b9d59a5 100644 --- a/drivers/net/dwc_eth_qos.c +++ b/drivers/net/dwc_eth_qos.c @@ -1431,8 +1431,10 @@ static int eqos_free_pkt(struct udevice *dev, uchar *packet, int length) rx_desc = &(eqos->rx_descs[eqos->rx_desc_idx]); + rx_desc->des0 = 0; + mb(); + eqos->config->ops->eqos_flush_desc(rx_desc); eqos->config->ops->eqos_inval_buffer(packet, length); - rx_desc->des0 = (u32)(ulong)packet; rx_desc->des1 = 0; rx_desc->des2 = 0; -- 2.25.1
