net: dwc_eth_qos: Invalidate RX descriptor before reading

The current code polls the RX desciptor ring for new packets by reading
the RX descriptor status. This works by accident, as the RX descriptors
are often in non-cacheable memory. However, the driver does support use
of RX descriptors in cacheable memory.

This patch adds a missing RX descriptor invalidation, which assures the
CPU will read a fresh copy of the RX descriptor instead of a cached one.

Reviewed-by: Patrick Delaunay <patrick.delaunay@st.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Patrick Delaunay <patrick.delaunay@st.com>
Cc: Ramon Fried <rfried.dev@gmail.com>
Cc: Stephen Warren <swarren@nvidia.com>
This commit is contained in:
Marek Vasut 2020-03-23 02:09:21 +01:00 committed by marex
parent dd90c2e1ea
commit 738ee270fe

View File

@ -1443,6 +1443,7 @@ static int eqos_recv(struct udevice *dev, int flags, uchar **packetp)
debug("%s(dev=%p, flags=%x):\n", __func__, dev, flags);
rx_desc = &(eqos->rx_descs[eqos->rx_desc_idx]);
eqos->config->ops->eqos_inval_desc(rx_desc);
if (rx_desc->des3 & EQOS_DESC3_OWN) {
debug("%s: RX packet not available\n", __func__);
return -EAGAIN;