tsnep: Subtract TSNEP_RX_INLINE_METADATA_SIZE once

Subtract size of metadata in front of received data only once. This
simplifies the RX code.

Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/engleder/tsnep_main.c b/drivers/net/ethernet/engleder/tsnep_main.c
index 9b3eddda3f060e2c2f607b583d3b149ae95d9368..0730cd45f9a37ca123b15a4ac01a0ec3ff97d44e 100644 (file)
--- a/drivers/net/ethernet/engleder/tsnep_main.c
+++ b/drivers/net/ethernet/engleder/tsnep_main.c
@@ -948,7 +948,7 @@ static struct sk_buff *tsnep_build_skb(struct tsnep_rx *rx, struct page *page,
 
        /* update pointers within the skb to store the data */
        skb_reserve(skb, TSNEP_SKB_PAD + TSNEP_RX_INLINE_METADATA_SIZE);
-       __skb_put(skb, length - TSNEP_RX_INLINE_METADATA_SIZE - ETH_FCS_LEN);
+       __skb_put(skb, length - ETH_FCS_LEN);
 
        if (rx->adapter->hwtstamp_config.rx_filter == HWTSTAMP_FILTER_ALL) {
                struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
@@ -1020,6 +1020,13 @@ static int tsnep_rx_poll(struct tsnep_rx *rx, struct napi_struct *napi,
                dma_sync_single_range_for_cpu(dmadev, entry->dma, TSNEP_SKB_PAD,
                                              length, dma_dir);
 
+               /* RX metadata with timestamps is in front of actual data,
+                * subtract metadata size to get length of actual data and
+                * consider metadata size as offset of actual data during RX
+                * processing
+                */
+               length -= TSNEP_RX_INLINE_METADATA_SIZE;
+
                rx->read = (rx->read + 1) % TSNEP_RING_SIZE;
                desc_available++;
 
@@ -1028,7 +1035,7 @@ static int tsnep_rx_poll(struct tsnep_rx *rx, struct napi_struct *napi,
                        page_pool_release_page(rx->page_pool, entry->page);
 
                        rx->packets++;
-                       rx->bytes += length - TSNEP_RX_INLINE_METADATA_SIZE;
+                       rx->bytes += length;
                        if (skb->pkt_type == PACKET_MULTICAST)
                                rx->multicast++;