[PATCH v2] ethernet/arc/arc_emac - Add new driver
Joe Perches
joe at perches.com
Sat Jun 8 04:13:03 EST 2013
On Fri, 2013-06-07 at 19:07 +0400, Alexey Brodkin wrote:
> Driver for non-standard on-chip ethernet device ARC EMAC 10/100,
> instantiated in some legacy ARC (Synopsys) FPGA Boards such as
> ARCAngel4/ML50x.
trivial comments only:
> diff --git a/drivers/net/ethernet/arc/arc_emac_main.c b/drivers/net/ethernet/arc/arc_emac_main.c
[]
> @@ -0,0 +1,956 @@
> +/*
> + * Copyright (C) 2004, 2007-2010, 2011-2013 Synopsys, Inc. (www.synopsys.com)
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * Driver for the ARC EMAC 10100 (Rev 5)
> + *
> + * Alexey Brodkin: June 2013
> + * -Upsteaming
[]
> + * Vineet Gupta: June 2011
> + * -Issues when working with 64b cache line size
[]
> + * Vineet Gupta: May 2010
> + * -Reduced foot-print of the main ISR (handling for error cases moved out
[]
> + * Vineet Gupta: Nov 2009
> + * -Unified NAPI and Non-NAPI Code.
[]
> + * Vineet Gupta: Nov 2009
[]
> + * Amit Bhor, Sameer Dhavale: 2004
Does the internal changelog add anything useful?
> +static int arc_emac_poll(struct napi_struct *napi, int budget)
> +{
> + struct net_device *net_dev = napi->dev;
> + struct arc_emac_priv *priv = netdev_priv(net_dev);
> + struct sk_buff *skb, *skbnew;
> + unsigned int i, loop, len, info, work_done = 0;
> +
> + /* Loop thru the BD chain, but not always from 0.
> + * Start from right after where we last saw a packet.
> + */
> + i = priv->last_rx_bd;
> +
> + for (loop = 0; loop < RX_BD_NUM; loop++) {
> + i = (i + 1) & (RX_BD_NUM - 1);
> +
> + info = priv->rxbd[i].info;
> +
> + /* BD contains a packet for CPU to grab */
> + if (likely((info & OWN_MASK) == FOR_CPU)) {
You could reduce indentation a level for all
the lines that follow by using
if (unlikely(!(...)
continue;
> + /* Get a new SKB from stack */
> + skbnew = netdev_alloc_skb(net_dev,
> + net_dev->mtu +
> + EMAC_BUFFER_PAD);
> +
> + if (!skbnew) {
> + netdev_err(net_dev, "Out of memory, "
> + "dropping packet\n");
OOM messages aren't particularly useful,
and coalesce format please...
[]
> + netdev_warn(net_dev,
> + "Rx chained, packet is larger than "
> + "device MTU (%d bytes)\n",
> + net_dev->mtu);
Same here.
> +static irqreturn_t arc_emac_intr(int irq, void *dev_instance)
> +{
> + struct net_device *net_dev = (struct net_device *)dev_instance;
Don't need to cast void *
netdev is a more common variable name
> + if (status & TXINT_MASK) {
> + unsigned int i, info;
> + struct sk_buff *skb;
[]
> + if (status & TXCH_MASK) {
> + priv->stats.tx_errors++;
> + priv->stats.tx_aborted_errors++;
> + netdev_err(priv->net_dev,
> + "Tx chaining err! txbd_dirty = %u\n",
> + priv->txbd_dirty);
You already have a local net_dev.
why not use that?
> + } else {
> + netdev_err(priv->net_dev,
> + "unknown err. Status reg is 0x%x\n",
> + status);
here too.
> +int arc_emac_open(struct net_device *net_dev)
> +{
> + struct arc_emac_priv *priv = netdev_priv(net_dev);
> + struct arc_emac_bd_t *bd;
> + struct sk_buff *skb;
> + int i;
> +
> + if (!priv->phy_node) {
> + netdev_err(net_dev, "arc_emac_open: phy device is absent\n");
If you really need the function name,
it's better to use "%s: ", __func__
> +int arc_emac_tx(struct sk_buff *skb, struct net_device *net_dev)
> +{
[]
> +tx_next_chunk:
> +
> + info = priv->txbd[priv->txbd_curr].info;
> + if (likely((info & OWN_MASK) == FOR_CPU)) {
if (unlikely(!(etc...)
return NETDEV_TX_BUSY;
and save an indent level
> +/**
> +int arc_emac_set_address(struct net_device *net_dev, void *p)
[]
> + EMAC_REG_SET(priv->reg_base_addr, R_ADDRH,
> + *(unsigned int *)&net_dev->dev_addr[4] & 0x0000ffff);
That doesn't seem endian friendly.
> +static int arc_emac_probe(struct platform_device *pdev)
> +{
[]
> + /* Get phy from device tree */
> + priv->phy_node = of_parse_phandle(pdev->dev.of_node, "phy", 0);
> + if (!priv->phy_node) {
> + dev_err(&pdev->dev, "failed to retrieve phy description "
> + "from device tree\n");
Coalesce formats please
> + err = of_address_to_resource(pdev->dev.of_node, 0, &res_regs);
> + if (err) {
> + dev_err(&pdev->dev, "failed to retrieve registers base "
> + "from device tree\n");
[]
> + /* Get IRQ from device tree */
> + err = of_irq_to_resource(pdev->dev.of_node, 0, &res_irq);
> + if (!err) {
> + dev_err(&pdev->dev, "failed to retrieve <irq> value "
> + "from device tree\n");
[]
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