From patchwork Fri Oct 2 13:29:04 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dean Jenkins X-Patchwork-Id: 525510 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 0FF6C1402B3 for ; Fri, 2 Oct 2015 23:31:40 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753557AbbJBNbc (ORCPT ); Fri, 2 Oct 2015 09:31:32 -0400 Received: from relay1.mentorg.com ([192.94.38.131]:47511 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752648AbbJBNba (ORCPT ); Fri, 2 Oct 2015 09:31:30 -0400 Received: from nat-ies.mentorg.com ([192.94.31.2] helo=SVR-IES-FEM-02.mgc.mentorg.com) by relay1.mentorg.com with esmtp id 1Zi0PU-00056y-Sw from Dean_Jenkins@mentor.com ; Fri, 02 Oct 2015 06:30:05 -0700 Received: from localhost.world.mentorg.com (137.202.0.76) by SVR-IES-FEM-02.mgc.mentorg.com (137.202.0.106) with Microsoft SMTP Server id 14.3.224.2; Fri, 2 Oct 2015 14:30:04 +0100 From: Dean Jenkins To: CC: , , , , , Mark Craske , Dean Jenkins Subject: [PATCH v1 1/5] asix: Rename remaining and size for clarity Date: Fri, 2 Oct 2015 14:29:04 +0100 Message-ID: <1443792548-2025-2-git-send-email-Dean_Jenkins@mentor.com> X-Mailer: git-send-email 1.8.5.6 In-Reply-To: <1443792548-2025-1-git-send-email-Dean_Jenkins@mentor.com> References: <1443792548-2025-1-git-send-email-Dean_Jenkins@mentor.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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 --- 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 5d049d0..a2d3ea6 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 75d6f26..2bd5bdd 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) {