Commit a88c32ae authored by Ming Lei's avatar Ming Lei Committed by David S. Miller
Browse files

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: default avatarMing Lei <ming.lei@canonical.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6680ec68

drivers/net/usb/asix_devices.c

+3 −0
Original line number Diff line number Diff line
@@ -778,6 +778,9 @@ static int ax88178_change_mtu(struct net_device *net, int new_mtu) 
	dev->hard_mtu = net->mtu + net->hard_header_len;

	ax88178_set_mfb(dev);



	/* max qlen depend on hard_mtu and rx_urb_size */

	usbnet_update_max_qlen(dev);



	return 0;

}

drivers/net/usb/ax88179_178a.c

+3 −0
Original line number Diff line number Diff line
@@ -688,6 +688,9 @@ static int ax88179_change_mtu(struct net_device *net, int new_mtu) 
				  2, 2, &tmp16);

	}



	/* max qlen depend on hard_mtu and rx_urb_size */

	usbnet_update_max_qlen(dev);



	return 0;

}

drivers/net/usb/usbnet.c

+37 −8
Original line number Diff line number Diff line
@@ -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;

include/linux/usb/usbnet.h

+3 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ struct usbnet { 
	struct mutex		phy_mutex;

	unsigned char		suspend_count;

	unsigned char		pkt_cnt, pkt_err;

	unsigned short		rx_qlen, tx_qlen;



	/* i/o info: pipes etc */

	unsigned		in, out;
@@ -253,4 +254,6 @@ extern void usbnet_link_change(struct usbnet *, bool, bool); 
extern int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags);

extern void usbnet_status_stop(struct usbnet *dev);



extern void usbnet_update_max_qlen(struct usbnet *dev);



#endif /* __LINUX_USB_USBNET_H */

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