net: ethernet: mtk_eth_soc: rely on txd_size field in mtk_poll_tx/mtk_poll_rx

This is a preliminary to ad mt7986 ethernet support.
Tested-by: NSam Shih <sam.shih@mediatek.com>
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/mediatek/mtk_eth_soc.c

@@ -1235,9 +1235,12 @@ static struct mtk_rx_ring *mtk_get_rx_ring(struct mtk_eth *eth)
 		return &eth->rx_ring[0];
 
 	for (i = 0; i < MTK_MAX_RX_RING_NUM; i++) {
+		struct mtk_rx_dma *rxd;
+
 		ring = &eth->rx_ring[i];
 		idx = NEXT_DESP_IDX(ring->calc_idx, ring->dma_size);
-		if (ring->dma[idx].rxd2 & RX_DMA_DONE) {
+		rxd = (void *)ring->dma + idx * eth->soc->txrx.rxd_size;
+		if (rxd->rxd2 & RX_DMA_DONE) {
 			ring->calc_idx_update = true;
 			return ring;
 		}
@@ -1288,7 +1291,7 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
 			goto rx_done;
 
 		idx = NEXT_DESP_IDX(ring->calc_idx, ring->dma_size);
-		rxd = &ring->dma[idx];
+		rxd = (void *)ring->dma + idx * eth->soc->txrx.rxd_size;
 		data = ring->data[idx];
 
 		if (!mtk_rx_get_desc(&trxd, rxd))
@@ -1477,7 +1480,7 @@ static int mtk_poll_tx_pdma(struct mtk_eth *eth, int budget,
 
 		mtk_tx_unmap(eth, tx_buf, true);
 
-		desc = &ring->dma[cpu];
+		desc = (void *)ring->dma + cpu * eth->soc->txrx.txd_size;
 		ring->last_free = desc;
 		atomic_inc(&ring->free_count);