From 7b0378f517fa1a32b5c8384248d2f8bf79c7c2ae Mon Sep 17 00:00:00 2001 From: Dean Jenkins Date: Fri, 2 Oct 2015 14:29:04 +0100 Subject: [PATCH] asix: Rename remaining and size for clarity The Data header synchronisation is easier to understand if the variables "remaining" and "size" are renamed. Therefore, the lifetime of the "remaining" variable exists outside of asix_rx_fixup_internal() and is used to indicate any remaining pending bytes of the Ethernet frame that need to be obtained from the next socket buffer. This allows an Ethernet frame to span across multiple socket buffers. "size" is now local to asix_rx_fixup_internal() and contains the size read from the Data header 32-bit word. Add "copy_length" to hold the number of the Ethernet frame bytes (maybe a part of a full frame) that are to be copied out of the socket buffer. Signed-off-by: Dean Jenkins Signed-off-by: Mark Craske Signed-off-by: David S. Miller --- drivers/net/usb/asix.h | 2 +- drivers/net/usb/asix_common.c | 41 ++++++++++++++++++----------------- 2 files changed, 22 insertions(+), 21 deletions(-) diff --git a/drivers/net/usb/asix.h b/drivers/net/usb/asix.h index 5d049d00c2d7..a2d3ea6efb20 100644 --- a/drivers/net/usb/asix.h +++ b/drivers/net/usb/asix.h @@ -168,7 +168,7 @@ struct asix_data { struct asix_rx_fixup_info { struct sk_buff *ax_skb; u32 header; - u16 size; + u16 remaining; bool split_head; }; diff --git a/drivers/net/usb/asix_common.c b/drivers/net/usb/asix_common.c index 75d6f26729a3..2bd5bdda8c2e 100644 --- a/drivers/net/usb/asix_common.c +++ b/drivers/net/usb/asix_common.c @@ -54,12 +54,13 @@ int asix_rx_fixup_internal(struct usbnet *dev, struct sk_buff *skb, struct asix_rx_fixup_info *rx) { int offset = 0; + u16 size; while (offset + sizeof(u16) <= skb->len) { - u16 remaining = 0; + u16 copy_length; unsigned char *data; - if (!rx->size) { + if (!rx->remaining) { if ((skb->len - offset == sizeof(u16)) || rx->split_head) { if(!rx->split_head) { @@ -81,42 +82,42 @@ int asix_rx_fixup_internal(struct usbnet *dev, struct sk_buff *skb, offset += sizeof(u32); } - /* get the packet length */ - rx->size = (u16) (rx->header & 0x7ff); - if (rx->size != ((~rx->header >> 16) & 0x7ff)) { + /* take frame length from Data header 32-bit word */ + size = (u16)(rx->header & 0x7ff); + if (size != ((~rx->header >> 16) & 0x7ff)) { netdev_err(dev->net, "asix_rx_fixup() Bad Header Length 0x%x, offset %d\n", rx->header, offset); - rx->size = 0; return 0; } - rx->ax_skb = netdev_alloc_skb_ip_align(dev->net, - rx->size); + rx->ax_skb = netdev_alloc_skb_ip_align(dev->net, size); if (!rx->ax_skb) return 0; + rx->remaining = size; } - if (rx->size > dev->net->mtu + ETH_HLEN + VLAN_HLEN) { + if (rx->remaining > dev->net->mtu + ETH_HLEN + VLAN_HLEN) { netdev_err(dev->net, "asix_rx_fixup() Bad RX Length %d\n", - rx->size); + rx->remaining); kfree_skb(rx->ax_skb); rx->ax_skb = NULL; - rx->size = 0U; - + rx->remaining = 0; return 0; } - if (rx->size > skb->len - offset) { - remaining = rx->size - (skb->len - offset); - rx->size = skb->len - offset; + if (rx->remaining > skb->len - offset) { + copy_length = skb->len - offset; + rx->remaining -= copy_length; + } else { + copy_length = rx->remaining; + rx->remaining = 0; } - data = skb_put(rx->ax_skb, rx->size); - memcpy(data, skb->data + offset, rx->size); - if (!remaining) + data = skb_put(rx->ax_skb, copy_length); + memcpy(data, skb->data + offset, copy_length); + if (!rx->remaining) usbnet_skb_return(dev, rx->ax_skb); - offset += (rx->size + 1) & 0xfffe; - rx->size = remaining; + offset += (copy_length + 1) & 0xfffe; } if (skb->len != offset) { -- 2.39.5