Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932376Ab3GVRLV (ORCPT ); Mon, 22 Jul 2013 13:11:21 -0400 Received: from webmail.solarflare.com ([12.187.104.25]:10437 "EHLO webmail.solarflare.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757398Ab3GVRLT (ORCPT ); Mon, 22 Jul 2013 13:11:19 -0400 Message-ID: <1374513075.1635.14.camel@bwh-desktop.uk.level5networks.com> Subject: Re: [PATCH 1/1] TX throttling bug-fixing patch of AX88179_178A From: Ben Hutchings To: Eric Dumazet CC: , , , , , , , Date: Mon, 22 Jul 2013 18:11:15 +0100 In-Reply-To: <1374512879.4990.19.camel@edumazet-glaptop> References: <1374311809-4155-1-git-send-email-freddy@asix.com.tw> <1374512879.4990.19.camel@edumazet-glaptop> Organization: Solarflare Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.4 (3.6.4-3.fc18) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Originating-IP: [10.17.20.137] X-TM-AS-Product-Ver: SMEX-10.0.0.1412-7.000.1014-20030.005 X-TM-AS-Result: No--18.210300-0.000000-31 X-TM-AS-User-Approved-Sender: Yes X-TM-AS-User-Blocked-Sender: No Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2059 Lines: 54 On Mon, 2013-07-22 at 10:07 -0700, Eric Dumazet wrote: > On Sat, 2013-07-20 at 17:16 +0800, freddy@asix.com.tw wrote: > > From: Freddy Xin > > > > Disable TSO and SG network features in reset() and bind() functions, > > and check the return value of skb_linearize() in tx_fixup() to prevent > > TX throttling. > > > > Signed-off-by: Freddy Xin > > --- > > drivers/net/usb/ax88179_178a.c | 8 +++++--- > > 1 file changed, 5 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c > > index 1e3c302..eb71331 100644 > > --- a/drivers/net/usb/ax88179_178a.c > > +++ b/drivers/net/usb/ax88179_178a.c > > @@ -1029,7 +1029,7 @@ static int ax88179_bind(struct usbnet *dev, struct usb_interface *intf) > > dev->mii.supports_gmii = 1; > > > > dev->net->features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | > > - NETIF_F_RXCSUM | NETIF_F_SG | NETIF_F_TSO; > > + NETIF_F_RXCSUM; > > > > dev->net->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | > > NETIF_F_RXCSUM | NETIF_F_SG | NETIF_F_TSO; > > @@ -1173,7 +1173,9 @@ ax88179_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags) > > if (((skb->len + 8) % frame_size) == 0) > > tx_hdr2 |= 0x80008000; /* Enable padding */ > > > > - skb_linearize(skb); > > + if (skb_linearize(skb)) > > + return NULL; > > + > > > > I guess that if a driver does not advertise NETIF_F_SG, this > skb_linearize() call is not needed : All frames reaching your xmit > function should already be linear Look at the hw_features initialisation... Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/