Re: [PATCH net-next 5/8] net: lantiq: configure the burst length in ethernet drivers
From: Hauke Mehrtens <hauke@hauke-m.de>
Date: 2021-09-14 22:36:52
Also in:
linux-mips, lkml, netdev
On 9/14/21 11:21 PM, Aleksander Jan Bajkowski wrote:
Configure the burst length in Ethernet drivers. This improves Ethernet performance by 58%. According to the vendor BSP, 8W burst length is supported by ar9 and newer SoCs. The NAT benchmark results on xRX200 (Down/Up): * 2W: 330 Mb/s * 4W: 432 Mb/s 372 Mb/s * 8W: 520 Mb/s 389 Mb/s Tested on xRX200 and xRX330. Signed-off-by: Aleksander Jan Bajkowski <redacted> --- drivers/net/ethernet/lantiq_etop.c | 21 ++++++++++++++++++--- drivers/net/ethernet/lantiq_xrx200.c | 21 ++++++++++++++++++--- 2 files changed, 36 insertions(+), 6 deletions(-)
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quoted hunk ↗ jump to hunk
diff --git a/drivers/net/ethernet/lantiq_xrx200.c b/drivers/net/ethernet/lantiq_xrx200.c index fb78f17d734f..5d96248ce83b 100644 --- a/drivers/net/ethernet/lantiq_xrx200.c +++ b/drivers/net/ethernet/lantiq_xrx200.c@@ -71,6 +71,9 @@ struct xrx200_priv { struct net_device *net_dev; struct device *dev; + int tx_burst_len; + int rx_burst_len; + __iomem void *pmac_reg; };@@ -316,8 +319,8 @@ static netdev_tx_t xrx200_start_xmit(struct sk_buff *skb, if (unlikely(dma_mapping_error(priv->dev, mapping))) goto err_drop; - /* dma needs to start on a 16 byte aligned address */ - byte_offset = mapping % 16; + /* dma needs to start on a burst length value aligned address */ + byte_offset = mapping % (priv->tx_burst_len * 4); desc->addr = mapping - byte_offset; /* Make sure the address is written before we give it to HW */@@ -369,7 +372,7 @@ static int xrx200_dma_init(struct xrx200_priv *priv) int ret = 0; int i; - ltq_dma_init_port(DMA_PORT_ETOP); + ltq_dma_init_port(DMA_PORT_ETOP, priv->tx_burst_len, rx_burst_len); ch_rx->dma.nr = XRX200_DMA_RX; ch_rx->dma.dev = priv->dev;@@ -478,6 +481,18 @@ static int xrx200_probe(struct platform_device *pdev) if (err) eth_hw_addr_random(net_dev); + err = device_property_read_u32(dev, "lantiq,tx-burst-length", &priv->tx_burst_len); + if (err < 0) { + dev_err(dev, "unable to read tx-burst-length property\n"); + return err; + } + + err = device_property_read_u32(dev, "lantiq,rx-burst-length", &priv->rx_burst_len); + if (err < 0) { + dev_err(dev, "unable to read rx-burst-length property\n"); + return err; + } +
I would prefer if you would hard code these values to 8 for the xrx200 driver. All SoCs with this IP block should support this.
/* bring up the dma engine and IP core */ err = xrx200_dma_init(priv); if (err)
Hauke