target/linux/generic/backport-6.1/796-v6.5-02-usbnet-ipheth-transmit-URBs-without-trailing-padding.patch

   1 From 3e65efcca87a9bb5f3b864e0a43d167bc0a8688c Mon Sep 17 00:00:00 2001
   2 From: Foster Snowhill <forst@pen.gy>
   3 Date: Wed, 7 Jun 2023 15:57:00 +0200
   4 Subject: [PATCH 2/4] usbnet: ipheth: transmit URBs without trailing padding
   5
   6 The behaviour of the official iOS tethering driver on macOS is to not
   7 transmit any trailing padding at the end of URBs. This is applicable
   8 to both NCM and legacy modes, including older devices.
   9
  10 Adapt the driver to not include trailing padding in TX URBs, matching
  11 the behaviour of the official macOS driver.
  12
  13 Signed-off-by: Foster Snowhill <forst@pen.gy>
  14 Tested-by: Georgi Valkov <gvalkov@gmail.com>
  15 Signed-off-by: David S. Miller <davem@davemloft.net>
  16 ---
  17  drivers/net/usb/ipheth.c | 4 +---
  18  1 file changed, 1 insertion(+), 3 deletions(-)
  19
  20 --- a/drivers/net/usb/ipheth.c
  21 +++ b/drivers/net/usb/ipheth.c
  22 @@ -373,12 +373,10 @@ static netdev_tx_t ipheth_tx(struct sk_b
  23         }
  24
  25         memcpy(dev->tx_buf, skb->data, skb->len);
  26 -       if (skb->len < IPHETH_BUF_SIZE)
  27 -               memset(dev->tx_buf + skb->len, 0, IPHETH_BUF_SIZE - skb->len);
  28
  29         usb_fill_bulk_urb(dev->tx_urb, udev,
  30                           usb_sndbulkpipe(udev, dev->bulk_out),
  31 -                         dev->tx_buf, IPHETH_BUF_SIZE,
  32 +                         dev->tx_buf, skb->len,
  33                           ipheth_sndbulk_callback,
  34                           dev);
  35         dev->tx_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;