Hi Stephen,
thank you for your suggestions.
I already applied trivial fixes, but I have questions on some points,
see inline.
Stephen Hemminger wrote:
General comments:
* device driver does no carrier detection. This makes it useless
for bridging, bonding, or any form of failover.
* use msglevel method (via ethtool) to control debug messages
rather than kernel configuration. This allows enabling debugging
without recompilation which is important in distributions.
* Please add ethtool support
* Consider using NAPI
Can you point me to a possibly simple driver that uses ethtool and NAPI?
Or other example that I can use for reference.
May be the skeleton should be updated.
* use netdev_priv(netdev) rather than netdev->priv
I can't find where I used netdev->priv, may be do you mean priv->netdev?
My comments:
diff --git a/drivers/net/enc28j60.c b/drivers/net/enc28j60.c
new file mode 100644
index 0000000..6182473
--- /dev/null
+++ b/drivers/net/enc28j60.c
@@ -0,0 +1,1400 @@
+/*
+ * Microchip ENC28J60 ethernet driver (MAC + PHY)
+ *
+ * Copyright (C) 2007 Eurek srl
+ * Author: Claudio Lanconelli <[EMAIL PROTECTED]>
+ * based on enc28j60.c written by David Anders for 2.4 kernel version
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * $Id: enc28j60.c,v 1.10 2007/12/10 16:59:37 claudio Exp $
+ */
+
+#include <linux/autoconf.h>
Use msglvl instead see netdevice.h
Ok
+
+#if CONFIG_ENC28J60_DBGLEVEL > 1
+# define VERBOSE_DEBUG
+#endif
+#if CONFIG_ENC28J60_DBGLEVEL > 0
+# define DEBUG
+#endif
+
...
+
+#define MY_TX_TIMEOUT ((500*HZ)/1000)
That is a really short TX timeout, should be 2 seconds at least not 1/2 sec.
Having it less than a second causes increased wakeups.
Ok
+
+/* Max TX retries in case of collision as suggested by errata datasheet */
+#define MAX_TX_RETRYCOUNT 16
+
+/* Driver local data */
+struct enc28j60_net_local {
Rename something shorter like enc28j60_net or just enc28j60?
Ok, renamed enc28j60_net
+ struct net_device_stats stats;
net_device_stats are now in net_device.
+ struct net_device *netdev;
+ struct spi_device *spi;
+ struct semaphore semlock; /* protect spi_transfer_buf */
Use mutex (or spin_lock) rather than semaphore
Ok
+ uint8_t *spi_transfer_buf;
+ struct sk_buff *tx_skb;
+ struct work_struct tx_work;
+ struct work_struct irq_work;
Not sure why you need to have workqueue's for
tx_work and irq_work, rather than using a spin_lock
and doing directly.
I need irq_work for sure because it needs to go sleep. Any
access to enc28j60 registers are through SPI blocking transaction,
spi_sync().
I'm not sure if the hard_start_xmit() can go sleep, so I used a work
queue to tx too.
+ int bank; /* current register bank selected */
bank is really unsigned.
+ uint16_t next_pk_ptr; /* next packet pointer within FIFO */
+ int max_pk_counter; /* statistics: max packet counter */
+ int tx_retry_count;
these are used as unsigned.
+ int hw_enable;
+};
+
+/* Selects Full duplex vs. Half duplex mode */
+static int full_duplex = 0;
Use ethtool for this.
Ok
+
+static int enc28j60_send_packet(struct sk_buff *skb, struct net_device *dev);
+static int enc28j60_net_close(struct net_device *dev);
+static struct net_device_stats *enc28j60_net_get_stats(struct net_device *dev);
+static void enc28j60_set_multicast_list(struct net_device *dev);
+static void enc28j60_net_tx_timeout(struct net_device *ndev);
+
+static int enc28j60_chipset_init(struct net_device *dev);
+static void enc28j60_hw_disable(struct enc28j60_net_local *priv);
+static void enc28j60_hw_enable(struct enc28j60_net_local *priv);
+static void enc28j60_hw_rx(struct enc28j60_net_local *priv);
+static void enc28j60_hw_tx(struct enc28j60_net_local *priv);
If you order functions correctly in code, you don't have to waste lots
of space with all these forward declarations.
...
Ok
+ const char *msg);
+
+/*
+ * SPI read buffer
+ * wait for the SPI transfer and copy received data to destination
+ */
+static int
+spi_read_buf(struct enc28j60_net_local *priv, int len, uint8_t *data)
+{
+ uint8_t *rx_buf;
+ uint8_t *tx_buf;
+ struct spi_transfer t;
+ struct spi_message msg;
+ int ret, slen;
+
+ slen = 1;
+ memset(&t, 0, sizeof(t));
+ t.tx_buf = tx_buf = priv->spi_transfer_buf;
+ t.rx_buf = rx_buf = priv->spi_transfer_buf + 4;
+ t.len = slen + len;
If you use structure initializer you can avoid having to do
the memset
Ok
+
+ down(&priv->semlock);
+ tx_buf[0] = ENC28J60_READ_BUF_MEM;
+ tx_buf[1] = tx_buf[2] = tx_buf[3] = 0; /* don't care */
+
+ spi_message_init(&msg);
+ spi_message_add_tail(&t, &msg);
+ ret = spi_sync(priv->spi, &msg);
+ if (ret == 0) {
+ memcpy(data, &rx_buf[slen], len);
+ ret = msg.status;
+ }
+ up(&priv->semlock);
+ if (ret != 0)
+ dev_dbg(&priv->netdev->dev, "%s: failed: ret = %d\n",
+ __FUNCTION__, ret);
+
+ return ret;
+}
...
+/*
+ * Register word read
+ */
+static inline int enc28j60_regw_read(struct enc28j60_net_local *priv,
+ uint8_t address)
+{
I wouldn't bother marking these as "inline" since the compiler
will decide to inline in most cases. By telling the compiler to
inline it may generate bigger/slower code.
Ok
+ int rl, rh;
+
+ enc28j60_set_bank(priv, address);
+ rl = spi_read_op(priv, ENC28J60_READ_CTRL_REG, address);
+ rh = spi_read_op(priv, ENC28J60_READ_CTRL_REG, address + 1);
+
+ return (rh << 8) | rl;
+}
...
+/*
+ * Program the hardware MAC address from dev->dev_addr.
+ */
+static void enc28j60_set_hw_macaddr(struct enc28j60_net_local *priv)
+{
+ struct net_device *ndev = priv->netdev;
+
+ if (!priv->hw_enable) {
+ /* NOTE: MAC address in ENC28J60 is byte-backward */
+ enc28j60_regb_write(priv, MAADR5, ndev->dev_addr[0]);
+ enc28j60_regb_write(priv, MAADR4, ndev->dev_addr[1]);
+ enc28j60_regb_write(priv, MAADR3, ndev->dev_addr[2]);
+ enc28j60_regb_write(priv, MAADR2, ndev->dev_addr[3]);
+ enc28j60_regb_write(priv, MAADR1, ndev->dev_addr[4]);
+ enc28j60_regb_write(priv, MAADR0, ndev->dev_addr[5]);
+
+ dev_dbg(&ndev->dev,
+ "%s() [%s] Setting MAC address to "
+ "%02x:%02x:%02x:%02x:%02x:%02x\n",
+ __FUNCTION__, ndev->name, ndev->dev_addr[0],
+ ndev->dev_addr[1], ndev->dev_addr[2], ndev->dev_addr[3],
+ ndev->dev_addr[4], ndev->dev_addr[5]);
+ } else
+ dev_dbg(&ndev->dev,
+ "%s() Warning: hw must be disabled to set hw "
+ "Mac address\n", __FUNCTION__);
Should return -EINVAL/-EBUSY/... instead of printing message.
Ok
+}
+
+/*
+ * Store the new hardware address in dev->dev_addr, and update the MAC.
+ */
+static int enc28j60_set_mac_address(struct net_device *dev, void *addr)
+{
+ struct sockaddr *address = addr;
+ struct enc28j60_net_local *priv = netdev_priv(dev);
+
+ if (!is_valid_ether_addr(address->sa_data))
+ return -EADDRNOTAVAIL;
+
+ memcpy(dev->dev_addr, address->sa_data, dev->addr_len);
+ enc28j60_set_hw_macaddr(priv);
+
+ return 0;
+}
...
+
+/*
+ * Get the current statistics.
+ * This may be called with the card open or closed.
+ */
+static struct net_device_stats *enc28j60_net_get_stats(struct net_device *dev)
+{
+ struct enc28j60_net_local *priv = netdev_priv(dev);
+
+ return &priv->stats;
+}
If you use dev->stats, then you don't need your own get_stats function.
Ok
...
+static int enc28j60_hw_init(struct enc28j60_net_local *priv)
+{
+ uint8_t reg;
+
+ dev_dbg(&priv->spi->dev, "%s() - %s\n",
+ __FUNCTION__, full_duplex ? "FullDuplex" : "HalfDuplex");
+ /* first soft reset the chip */
+ enc28j60_soft_reset(priv);
+
+ dev_vdbg(&priv->spi->dev, "%s() bank0\n", __FUNCTION__);
+
+ /* Clear ECON1 */
+ spi_write_op(priv, ENC28J60_WRITE_CTRL_REG, ECON1, 0x00);
+ priv->bank = 0;
+ priv->hw_enable = 0;
+ priv->tx_retry_count = 0;
+
+ enc28j60_regb_write(priv, ECON2, ECON2_AUTOINC);
+ enc28j60_rxfifo_init(priv, RXSTART_INIT, RXEND_INIT);
+ enc28j60_txfifo_init(priv, TXSTART_INIT, TXEND_INIT);
+
+ /*
+ * Check the RevID.
+ * If it's 0x00 or 0xFF probably the enc28j60 is not mounted or
+ * damaged
+ */
+ reg = enc28j60_regb_read(priv, EREVID);
+ if (reg == 0x00 || reg == 0xff)
+ return 0;
+
+ dev_vdbg(&priv->spi->dev, "%s() bank1\n", __FUNCTION__);
+
+ /* default filter mode: (unicast OR broadcast) AND crc valid */
+ enc28j60_regb_write(priv, ERXFCON,
+ ERXFCON_UCEN | ERXFCON_CRCEN | ERXFCON_BCEN);
+
+ dev_vdbg(&priv->spi->dev, "%s() bank2\n", __FUNCTION__);
+ /* enable MAC receive */
+ enc28j60_regb_write(priv, MACON1,
+ MACON1_MARXEN | MACON1_TXPAUS | MACON1_RXPAUS);
+ /* enable automatic padding and CRC operations */
+ if (full_duplex) {
+ enc28j60_regb_write(priv, MACON3,
+ MACON3_PADCFG0 | MACON3_TXCRCEN |
+ MACON3_FRMLNEN | MACON3_FULDPX);
+ /* set inter-frame gap (non-back-to-back) */
+ enc28j60_regb_write(priv, MAIPGL, 0x12);
+ /* set inter-frame gap (back-to-back) */
+ enc28j60_regb_write(priv, MABBIPG, 0x15);
+ } else {
+ enc28j60_regb_write(priv, MACON3,
+ MACON3_PADCFG0 | MACON3_TXCRCEN |
+ MACON3_FRMLNEN);
+ enc28j60_regb_write(priv, MACON4, 1 << 6); /* DEFER bit
*/
+ /* set inter-frame gap (non-back-to-back) */
+ enc28j60_regw_write(priv, MAIPGL, 0x0C12);
+ /* set inter-frame gap (back-to-back) */
+ enc28j60_regb_write(priv, MABBIPG, 0x12);
+ }
+ /*
+ * MACLCON1 (default)
+ * MACLCON2 (default)
+ * Set the maximum packet size which the controller will accept
+ */
+ enc28j60_regw_write(priv, MAMXFLL, MAX_FRAMELEN);
+
+ dev_vdbg(&priv->spi->dev, "%s() bank3\n", __FUNCTION__);
+ /* NOTE: MAC address in ENC28J60 is byte-backward */
+ enc28j60_regb_write(priv, MAADR5, ENC28J60_MAC0);
+ enc28j60_regb_write(priv, MAADR4, ENC28J60_MAC1);
+ enc28j60_regb_write(priv, MAADR3, ENC28J60_MAC2);
+ enc28j60_regb_write(priv, MAADR2, ENC28J60_MAC3);
+ enc28j60_regb_write(priv, MAADR1, ENC28J60_MAC4);
+ enc28j60_regb_write(priv, MAADR0, ENC28J60_MAC5);
Rather than having same address, please use random_ether_addr()
to avoid problems with two devices with same ethernet address.
Ok
...
+static int __devinit enc28j60_probe(struct spi_device *spi)
+{
+ struct net_device *dev;
+ struct enc28j60_net_local *priv;
+ int ret = 0;
+
+ dev_dbg(&spi->dev, "%s() start\n", __FUNCTION__);
+
+ dev = alloc_etherdev(sizeof(struct enc28j60_net_local));
+ if (!dev) {
+ ret = -ENOMEM;
+ goto error_alloc;
+ }
+ priv = netdev_priv(dev);
+
+ priv->netdev = dev; /* priv to netdev reference */
+ priv->spi = spi; /* priv to spi reference */
+ priv->spi_transfer_buf = kmalloc(SPI_TRANSFER_BUF_LEN, GFP_KERNEL);
Why not declare the transfer buffer as an array in spi?
I don't understand exactly what do you mean here.
spi field point to struct spi_device from SPI subsystem.
Other SPI client driver uses an allocated buffer too.
Cheers,
Claudio Lanconelli
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