From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jose Abreu Subject: [PATCH v3 net-next 01/12] net: stmmac: Enable OSP for GMAC4 Date: Fri, 18 May 2018 14:55:58 +0100 Message-ID: <1dfd166fdfad67542e5e2ace11ee1983fe2ddf60.1526651009.git.joabreu@synopsys.com> References: Cc: Jose Abreu , "David S. Miller" , Joao Pinto , Vitor Soares , Giuseppe Cavallaro , Alexandre Torgue To: netdev@vger.kernel.org Return-path: Received: from smtprelay6.synopsys.com ([198.182.37.59]:57777 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752214AbeERN4r (ORCPT ); Fri, 18 May 2018 09:56:47 -0400 Received: from mailhost.synopsys.com (mailhost1.synopsys.com [10.12.238.239]) by smtprelay.synopsys.com (Postfix) with ESMTP id A923A1E05ED for ; Fri, 18 May 2018 15:56:45 +0200 (CEST) In-Reply-To: In-Reply-To: References: Sender: netdev-owner@vger.kernel.org List-ID: This enables OSP (Operate on Second Packet) for GMAC4. The feature allows DMA to fetch second descriptor while its still processing the first one. Running iperf, the performance gain is +/- 38%. Signed-off-by: Jose Abreu Cc: David S. Miller Cc: Joao Pinto Cc: Vitor Soares Cc: Giuseppe Cavallaro Cc: Alexandre Torgue --- drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c index 117c3a5..9aab5b3 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c @@ -94,6 +94,10 @@ static void dwmac4_dma_init_tx_chan(void __iomem *ioaddr, value = readl(ioaddr + DMA_CHAN_TX_CONTROL(chan)); value = value | (txpbl << DMA_BUS_MODE_PBL_SHIFT); + + /* Enable OSP to get best performance */ + value |= DMA_CONTROL_OSP; + writel(value, ioaddr + DMA_CHAN_TX_CONTROL(chan)); writel(dma_tx_phy, ioaddr + DMA_CHAN_TX_BASE_ADDR(chan)); -- 1.7.1