net: fec_mxc: Fix DM driver issue in recv

When using ethernet DM driver, the recv interface has a
change with non-DM interface, that driver needs to set
the packet pointer and provide it to upper layer to process.

In fec driver, the fecmxc_recv functions does not handle the
packet pointer parameter. This may cause crash in upper layer
processing because the packet pointer is not set.

This patch allocates a buffer for the packet pointer and free it
through free_pkt interface.

Signed-off-by: Ye Li <ye.li@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/drivers/net/fec_mxc.c b/drivers/net/fec_mxc.c
index 29af85c..450cc0b 100644
--- a/drivers/net/fec_mxc.c
+++ b/drivers/net/fec_mxc.c
@@ -807,7 +807,16 @@
 	uint16_t bd_status;
 	ulong addr, size, end;
 	int i;
+
+#ifdef CONFIG_DM_ETH
+	*packetp = memalign(ARCH_DMA_MINALIGN, FEC_MAX_PKT_SIZE);
+	if (*packetp == 0) {
+		printf("%s: error allocating packetp\n", __func__);
+		return -ENOMEM;
+	}
+#else
 	ALLOC_CACHE_ALIGN_BUFFER(uchar, buff, FEC_MAX_PKT_SIZE);
+#endif
 
 	/* Check if any critical events have happened */
 	ievent = readl(&fec->eth->ievent);
@@ -883,8 +892,13 @@
 #ifdef CONFIG_FEC_MXC_SWAP_PACKET
 			swap_packet((uint32_t *)addr, frame_length);
 #endif
+
+#ifdef CONFIG_DM_ETH
+			memcpy(*packetp, (char *)addr, frame_length);
+#else
 			memcpy(buff, (char *)addr, frame_length);
 			net_process_received_packet(buff, frame_length);
+#endif
 			len = frame_length;
 		} else {
 			if (bd_status & FEC_RBD_ERR)
@@ -1202,10 +1216,19 @@
 	return fec_get_hwaddr(priv->dev_id, pdata->enetaddr);
 }
 
+static int fecmxc_free_pkt(struct udevice *dev, uchar *packet, int length)
+{
+	if (packet)
+		free(packet);
+
+	return 0;
+}
+
 static const struct eth_ops fecmxc_ops = {
 	.start			= fecmxc_init,
 	.send			= fecmxc_send,
 	.recv			= fecmxc_recv,
+	.free_pkt		= fecmxc_free_pkt,
 	.stop			= fecmxc_halt,
 	.write_hwaddr		= fecmxc_set_hwaddr,
 	.read_rom_hwaddr	= fecmxc_read_rom_hwaddr,