From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757941AbaE2RMs (ORCPT ); Thu, 29 May 2014 13:12:48 -0400 Received: from relay1.mentorg.com ([192.94.38.131]:56553 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757724AbaE2RMq (ORCPT ); Thu, 29 May 2014 13:12:46 -0400 From: Jim Baxter To: Felipe Balbi CC: Greg Kroah-Hartman , , , =?UTF-8?q?Bj=C3=B8rn=20Mork?= , Eric Dumazet , David Laight , Subject: [PATCH v1 3/3] usb: gadget: NCM: Stop RX TCP Bursts getting dropped. Date: Thu, 29 May 2014 18:12:23 +0100 Message-ID: <1401383543-10181-4-git-send-email-jim_baxter@mentor.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1401383543-10181-1-git-send-email-jim_baxter@mentor.com> References: <1401383543-10181-1-git-send-email-jim_baxter@mentor.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [137.202.0.76] X-OriginalArrivalTime: 29 May 2014 17:12:45.0778 (UTC) FILETIME=[35911B20:01CF7B61] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This fixes a problem with dropped packets over 16k CDC-NCM when the connection is being heavily used. The issue was that the skb truesize for the unpacked NCM packets was too high after they were cloned from the 16k skb, this lead to the potential memory calculated by the Kernel running out of memory earlier then it should. Signed-off-by: Jim Baxter --- drivers/usb/gadget/f_ncm.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/usb/gadget/f_ncm.c b/drivers/usb/gadget/f_ncm.c index 5452fb6..bcdc882 100644 --- a/drivers/usb/gadget/f_ncm.c +++ b/drivers/usb/gadget/f_ncm.c @@ -1229,16 +1229,17 @@ static int ncm_unwrap_ntb(struct gether *port, index2 = get_ncm(&tmp, opts->dgram_item_len); dg_len2 = get_ncm(&tmp, opts->dgram_item_len); - skb2 = skb_clone(skb, GFP_ATOMIC); + /* + * Copy the data into a new skb. + * This ensures the truesize is correct + */ + skb2 = netdev_alloc_skb_ip_align(ncm->netdev, + dg_len - crc_len); if (skb2 == NULL) goto err; + memcpy(skb_put(skb2, dg_len - crc_len), + skb->data + index, dg_len - crc_len); - if (!skb_pull(skb2, index)) { - ret = -EOVERFLOW; - goto err; - } - - skb_trim(skb2, dg_len - crc_len); skb_queue_tail(list, skb2); ndp_len -= 2 * (opts->dgram_item_len * 2); -- 1.7.9.5