stmmac: optimize tx desc management
This patch is to optimize the way to manage the TDES inside the
xmit function. When prepare the frame, some settings (e.g. OWN
bit) can be merged. This has been reworked to improve the tx
performances.
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 796d7c6..24c3608 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1991,8 +1991,10 @@
goto dma_map_err;
priv->tx_skbuff_dma[entry].buf = desc->des2;
priv->tx_skbuff_dma[entry].len = nopaged_len;
+ /* do not set the own at this stage */
priv->hw->desc->prepare_tx_desc(desc, 1, nopaged_len,
- csum_insertion, priv->mode);
+ csum_insertion, priv->mode, 0,
+ nfrags == 0);
} else {
desc = first;
entry = priv->hw->mode->jumbo_frm(priv, skb, csum_insertion);
@@ -2003,6 +2005,7 @@
for (i = 0; i < nfrags; i++) {
const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
int len = skb_frag_size(frag);
+ bool last_segment = (i == (nfrags - 1));
priv->tx_skbuff[entry] = NULL;
entry = STMMAC_GET_ENTRY(entry, DMA_TX_SIZE);
@@ -2021,19 +2024,12 @@
priv->tx_skbuff_dma[entry].map_as_page = true;
priv->tx_skbuff_dma[entry].len = len;
priv->hw->desc->prepare_tx_desc(desc, 0, len, csum_insertion,
- priv->mode);
- wmb();
- priv->hw->desc->set_tx_owner(desc);
- wmb();
+ priv->mode, 1, last_segment);
+ priv->tx_skbuff_dma[entry].last_segment = last_segment;
}
priv->tx_skbuff[entry] = skb;
- /* Finalize the latest segment. */
- priv->hw->desc->close_tx_desc(desc);
- priv->tx_skbuff_dma[entry].last_segment = true;
-
- wmb();
/* According to the coalesce parameter the IC bit for the latest
* segment could be reset and the timer re-started to invoke the
* stmmac_tx function. This approach takes care about the fragments.