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Commit 7723ba18 authored by Tarun Gupta's avatar Tarun Gupta
Browse files

USB: u_ether: Increase the IN endpoint buffer allocation 



Some UDC may require allocation of some extra bytes for
TX buffer due to hardware requirement. Add necessary
changes for the same.

Change-Id: I2d0e636e0a876cce16077fa9929d92f13e383dd2
Signed-off-by: default avatarTarun Gupta <tarung@codeaurora.org>
parent c6641133

drivers/usb/gadget/function/u_ether.c

+31 −0
Original line number Diff line number Diff line
@@ -76,6 +76,9 @@ MODULE_PARM_DESC(min_cpu_freq, 
 */

#define DL_MAX_PKTS_PER_XFER	20



/* Extra buffer size to allocate for tx */

#define EXTRA_ALLOCATION_SIZE_U_ETH	128



enum ifc_state {

	ETH_UNDEFINED,

	ETH_STOP,
@@ -135,6 +138,7 @@ struct eth_dev { 
	unsigned int		tx_pkts_rcvd;

	unsigned int		tx_bytes_rcvd;

	unsigned int		loop_brk_cnt;

	unsigned long		skb_expand_cnt;

	struct dentry		*uether_dent;



	enum ifc_state		state;
@@ -1031,8 +1035,11 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb, 
{

	struct eth_dev		*dev = netdev_priv(net);

	int			length = 0;

	int			tail_room = 0;

	int			extra_alloc = 0;

	int			retval;

	struct usb_request	*req = NULL;

	struct sk_buff		*new_skb;

	unsigned long		flags;

	struct usb_ep		*in = NULL;

	u16			cdc_filter = 0;
@@ -1179,7 +1186,28 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb, 
		dev->tx_skb_hold_count = 0;

		spin_unlock_irqrestore(&dev->req_lock, flags);

	} else {

		/*

		 * Some UDC requires allocation of some extra bytes for

		 * TX buffer due to hardware requirement. Check if extra

		 * bytes are already there, otherwise allocate new buffer

		 * with extra bytes and do memcpy.

		 */

		length = skb->len;

		if (dev->gadget->extra_buf_alloc)

			extra_alloc = EXTRA_ALLOCATION_SIZE_U_ETH;

		tail_room = skb_tailroom(skb);

		if (tail_room < extra_alloc) {

			pr_debug("%s: tail_room  %d less than %d\n", __func__,

					tail_room, extra_alloc);

			new_skb = skb_copy_expand(skb, 0, extra_alloc -

					tail_room, GFP_ATOMIC);

			if (!new_skb)

				return -ENOMEM;

			dev_kfree_skb_any(skb);

			skb = new_skb;

			dev->skb_expand_cnt++;

		}



		req->buf = skb->data;

		req->context = skb;

	}
@@ -2188,6 +2216,8 @@ static int uether_stat_show(struct seq_file *s, void *unused) 
		seq_printf(s, "\nloop_brk_cnt = %u\n tx_pkts_rcvd=%u\n",

					dev->loop_brk_cnt,

					dev->tx_pkts_rcvd);

		seq_printf(s, "skb_expand_cnt = %lu\n",

					dev->skb_expand_cnt);

	}



	return ret;
@@ -2209,6 +2239,7 @@ static ssize_t uether_stat_reset(struct file *file, 
	/* Reset tx_throttle */

	dev->tx_throttle = 0;

	dev->rx_throttle = 0;

	dev->skb_expand_cnt = 0;

	spin_unlock_irqrestore(&dev->lock, flags);

	return count;

}