Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e93578bd authored by Saket Saurabh's avatar Saket Saurabh
Browse files

u_ether: Add tx_throttle count for rndis performance statistic 



Add tx_throttle count which signifies the number of times u_ether
forbid upper layer (network layer) to stop queueing packets to it
when transmit resources with u_ether are unavailable.
Keeping the tx_throttle count would help in getting statistic number
of how many times the network layer was throttled by the u_ether due
to unavailability of free tx_req list.

Also add debugfs entry for getting status and resetting of tx_throttle
cat /sys/kernel/debug/uether_rndis/status
echo 0 > /sys/kernel/debug/uether_rndis/status

Change-Id: Ia72494009e33a058060fd6b9441efcd0c136bb8e
Signed-off-by: default avatarSaket Saurabh <ssaurabh@codeaurora.org>
parent 27c6afde

drivers/usb/gadget/u_ether.c

+84 −2
Original line number Diff line number Diff line
@@ -23,7 +23,8 @@ 
#include <linux/ethtool.h>

#include <linux/if_vlan.h>

#include <linux/msm_rmnet.h>



#include <linux/debugfs.h>

#include <linux/seq_file.h>

#include "u_ether.h"
@@ -91,8 +92,14 @@ struct eth_dev { 


	bool			zlp;

	u8			host_mac[ETH_ALEN];

	unsigned long		tx_throttle;

	struct dentry		*uether_dent;

	struct dentry		*uether_dfile;

};



static void uether_debugfs_init(struct eth_dev *dev);

static void uether_debugfs_exit(struct eth_dev *dev);



/*-------------------------------------------------------------------------*/



#define RX_EXTRA	20	/* bytes guarding against rx overflows */
@@ -741,8 +748,15 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb, 
	list_del(&req->list);



	/* temporarily stop TX queue when the freelist empties */

	if (list_empty(&dev->tx_reqs))

	if (list_empty(&dev->tx_reqs)) {

		/*

		 * tx_throttle gives info about number of times u_ether

		 * asked network layer to stop queueing packets to it

		 * when transmit resources are unavailable

		 */

		dev->tx_throttle++;

		netif_stop_queue(net);

	}

	spin_unlock_irqrestore(&dev->req_lock, flags);



	/* no buffer copies needed, unless the network stack did it
@@ -1157,6 +1171,7 @@ struct eth_dev *gether_setup_name(struct usb_gadget *g, u8 ethaddr[ETH_ALEN], 
		 *  - tx queueing enabled if open *and* carrier is "on"

		 */

		netif_carrier_off(net);

		uether_debugfs_init(dev);

	}



	return dev;
@@ -1173,6 +1188,7 @@ void gether_cleanup(struct eth_dev *dev) 
	if (!dev)

		return;



	uether_debugfs_exit(dev);

	unregister_netdev(dev->net);

	flush_work(&dev->work);

	free_netdev(dev->net);
@@ -1336,6 +1352,11 @@ void gether_disconnect(struct gether *link) 
	link->out_ep->driver_data = NULL;

	link->out_ep->desc = NULL;



	pr_debug("%s(): tx_throttle count= %lu", __func__,

					dev->tx_throttle);

	/* reset tx_throttle count */

	dev->tx_throttle = 0;



	/* finish forgetting about this USB link episode */

	dev->header_len = 0;

	dev->unwrap = NULL;
@@ -1357,6 +1378,67 @@ int gether_up(struct gether *link) 
	return 0;

}





static int uether_stat_show(struct seq_file *s, void *unused)

{

	struct eth_dev *dev = s->private;

	int ret = 0;



	if (dev)

		seq_printf(s, "tx_throttle = %lu\n", dev->tx_throttle);

	return ret;

}



static int uether_open(struct inode *inode, struct file *file)

{

	return single_open(file, uether_stat_show, inode->i_private);

}



static ssize_t uether_stat_reset(struct file *file,

		const char __user *ubuf, size_t count, loff_t *ppos)

{

	struct seq_file *s = file->private_data;

	struct eth_dev *dev = s->private;

	unsigned long flags;



	spin_lock_irqsave(&dev->lock, flags);

	/* Reset tx_throttle */

	dev->tx_throttle = 0;

	spin_unlock_irqrestore(&dev->lock, flags);

	return count;

}



const struct file_operations uether_stats_ops = {

	.open = uether_open,

	.read = seq_read,

	.write = uether_stat_reset,

};



static void uether_debugfs_init(struct eth_dev *dev)

{

	struct dentry *uether_dent;

	struct dentry *uether_dfile;



	uether_dent = debugfs_create_dir("uether_rndis", 0);

	if (IS_ERR(uether_dent))

		return;

	dev->uether_dent = uether_dent;



	uether_dfile = debugfs_create_file("status", S_IRUGO | S_IWUSR,

				uether_dent, dev, &uether_stats_ops);

	if (!uether_dfile || IS_ERR(uether_dfile))

		debugfs_remove(uether_dent);

	dev->uether_dfile = uether_dfile;

}



static void uether_debugfs_exit(struct eth_dev *dev)

{

	debugfs_remove(dev->uether_dfile);

	debugfs_remove(dev->uether_dent);

	dev->uether_dent = NULL;

	dev->uether_dfile = NULL;

}



static int __init gether_init(void)

{

	uether_wq  = create_singlethread_workqueue("uether");