From ed909de5d3300f473e5ee5a520267c3e04b43b76 Mon Sep 17 00:00:00 2001 From: Andre Przywara Date: Mon, 6 Jul 2020 01:40:38 +0100 Subject: net: sun8i_emac: Reduce cache maintenance on TX descriptor init When we initialise the TX descriptors, there is no need yet to clean them all to memory, as they don't contain any data yet. Later we will touch and clean each descriptor anyway. However we tell the MAC about the beginning of the chain, so we have to clean at least the first descriptor, to make it clear that this is empty and there are no packets to transfer yet. Signed-off-by: Andre Przywara Acked-by: Maxime Ripard Tested-by: Amit Singh Tomar # Pine64+ Reviewed-by: Jagan Teki --- drivers/net/sun8i_emac.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/sun8i_emac.c b/drivers/net/sun8i_emac.c index c567b9e0827..335c85f3c26 100644 --- a/drivers/net/sun8i_emac.c +++ b/drivers/net/sun8i_emac.c @@ -431,10 +431,10 @@ static void tx_descs_init(struct emac_eth_dev *priv) /* Correcting the last pointer of the chain */ desc_p->next = (uintptr_t)&desc_table_p[0]; - /* Flush all Tx buffer descriptors */ + /* Flush the first TX buffer descriptor we will tell the MAC about. */ flush_dcache_range((uintptr_t)priv->tx_chain, (uintptr_t)priv->tx_chain + - sizeof(priv->tx_chain)); + sizeof(priv->tx_chain[0])); writel((uintptr_t)&desc_table_p[0], priv->mac_reg + EMAC_TX_DMA_DESC); priv->tx_currdescnum = 0; -- cgit v1.2.3