Merge "USB: u_ether: Align TX buffers to improve DL throughput" (03bb8ede) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/usb/gadget/function/u_ether.c

+16 −8

Original line number	Diff line number	Diff line
		@@ -174,7 +174,7 @@ static void uether_debugfs_exit(struct eth_dev *dev);
		* of interconnect, data can be very bursty. tx_qmult is the
		* additional multipler on qmult.
		*/
		static unsigned tx_qmult = 1;
		static unsigned tx_qmult = 2;
		module_param(tx_qmult, uint, S_IRUGO\|S_IWUSR);
		MODULE_PARM_DESC(tx_qmult, "Additional queue length multiplier for tx");

		@@ -1186,21 +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 {
		bool do_align = false;

		/* Check if TX buffer should be aligned before queuing to hw */
		if (!gadget_is_dwc3(dev->gadget) &&
		!IS_ALIGNED((size_t)skb->data, 4))
		do_align = true;

		/*
		* 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.
		* with extra bytes and do memcpy to align skb as well.
		*/
		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 (do_align \|\| tail_room < extra_alloc) {
		pr_debug("%s:align skb and update tail_room %d to %d\n",
		__func__, tail_room, extra_alloc);
		tail_room = extra_alloc;
		new_skb = skb_copy_expand(skb, 0, tail_room,
		GFP_ATOMIC);
		if (!new_skb)
		return -ENOMEM;
		dev_kfree_skb_any(skb);
		@@ -1208,6 +1215,7 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
		dev->skb_expand_cnt++;
		}

		length = skb->len;
		req->buf = skb->data;
		req->context = skb;
		}