net: qcom/emac: specify the correct size when mapping a DMA buffer

When mapping the RX DMA buffers, the driver was accidentally specifying
zero for the buffer length.  Under normal circumstances, SWIOTLB does not
need to allocate a bounce buffer, so the address is just mapped without
checking the size field.  This is why the error was not detected earlier.

Fixes: b9b17deb ("net: emac: emac gigabit ethernet controller driver")
Cc: stable@vger.kernel.org
Signed-off-by: Timur Tabi <timur@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/qualcomm/emac/emac-mac.c

@@ -898,7 +898,8 @@ static void emac_mac_rx_descs_refill(struct emac_adapter *adpt,
 
 		curr_rxbuf->dma_addr =
 			dma_map_single(adpt->netdev->dev.parent, skb->data,
-				       curr_rxbuf->length, DMA_FROM_DEVICE);
+				       adpt->rxbuf_size, DMA_FROM_DEVICE);
+
 		ret = dma_mapping_error(adpt->netdev->dev.parent,
 					curr_rxbuf->dma_addr);
 		if (ret) {