From a88c32ae15f25fcf0a3c9fadd92f840a1abf0e43 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 25 Jul 2013 13:47:53 +0800 Subject: USBNET: centralize computing of max rx/tx qlen This patch centralizes computing of max rx/tx qlen, because: - RX_QLEN()/TX_QLEN() is called in hot path - computing depends on device's usb speed, now we have ls/fs, hs, ss, so more checks need to be involved - in fact, max rx/tx qlen should not only depend on device USB speed, but also depend on ethernet link speed, so we need to consider that in future. - if SG support is done, max tx qlen may need change too Generally, hard_mtu and rx_urb_size are changed in bind(), reset() and link_reset() callback, and change mtu network operation, this patches introduces the API of usbnet_update_max_qlen(), and calls it in above path. Signed-off-by: Ming Lei Signed-off-by: David S. Miller --- drivers/net/usb/usbnet.c | 45 +++++++++++++++++++++++++++++++++++++-------- 1 file changed, 37 insertions(+), 8 deletions(-) (limited to 'drivers/net/usb/usbnet.c') diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index 06ee82f557d4..d74de074a438 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -59,15 +59,13 @@ * For high speed, each frame comfortably fits almost 36 max size * Ethernet packets (so queues should be bigger). * - * REVISIT qlens should be members of 'struct usbnet'; the goal is to - * let the USB host controller be busy for 5msec or more before an irq - * is required, under load. Jumbograms change the equation. + * The goal is to let the USB host controller be busy for 5msec or + * more before an irq is required, under load. Jumbograms change + * the equation. */ -#define RX_MAX_QUEUE_MEMORY (60 * 1518) -#define RX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \ - (RX_MAX_QUEUE_MEMORY/(dev)->rx_urb_size) : 4) -#define TX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \ - (RX_MAX_QUEUE_MEMORY/(dev)->hard_mtu) : 4) +#define MAX_QUEUE_MEMORY (60 * 1518) +#define RX_QLEN(dev) ((dev)->rx_qlen) +#define TX_QLEN(dev) ((dev)->tx_qlen) // reawaken network queue this soon after stopping; else watchdog barks #define TX_TIMEOUT_JIFFIES (5*HZ) @@ -347,6 +345,22 @@ void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb) } EXPORT_SYMBOL_GPL(usbnet_skb_return); +/* must be called if hard_mtu or rx_urb_size changed */ +void usbnet_update_max_qlen(struct usbnet *dev) +{ + enum usb_device_speed speed = dev->udev->speed; + + switch (speed) { + case USB_SPEED_HIGH: + dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size; + dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu; + break; + default: + dev->rx_qlen = dev->tx_qlen = 4; + } +} +EXPORT_SYMBOL_GPL(usbnet_update_max_qlen); + /*------------------------------------------------------------------------- * @@ -375,6 +389,9 @@ int usbnet_change_mtu (struct net_device *net, int new_mtu) usbnet_unlink_rx_urbs(dev); } + /* max qlen depend on hard_mtu and rx_urb_size */ + usbnet_update_max_qlen(dev); + return 0; } EXPORT_SYMBOL_GPL(usbnet_change_mtu); @@ -843,6 +860,9 @@ int usbnet_open (struct net_device *net) goto done; } + /* hard_mtu or rx_urb_size may change in reset() */ + usbnet_update_max_qlen(dev); + // insist peer be connected if (info->check_connect && (retval = info->check_connect (dev)) < 0) { netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval); @@ -927,6 +947,9 @@ int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd) if (dev->driver_info->link_reset) dev->driver_info->link_reset(dev); + /* hard_mtu or rx_urb_size may change in link_reset() */ + usbnet_update_max_qlen(dev); + return retval; } @@ -1020,6 +1043,9 @@ static void __handle_link_change(struct usbnet *dev) tasklet_schedule(&dev->bh); } + /* hard_mtu or rx_urb_size may change during link change */ + usbnet_update_max_qlen(dev); + clear_bit(EVENT_LINK_CHANGE, &dev->flags); } @@ -1599,6 +1625,9 @@ usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod) if ((dev->driver_info->flags & FLAG_WWAN) != 0) SET_NETDEV_DEVTYPE(net, &wwan_type); + /* initialize max rx_qlen and tx_qlen */ + usbnet_update_max_qlen(dev); + status = register_netdev (net); if (status) goto out4; -- cgit v1.2.3-59-g8ed1b