From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH 1/1] TX throttling bug-fixing patch of AX88179_178A Date: Mon, 22 Jul 2013 10:07:59 -0700 Message-ID: <1374512879.4990.19.camel@edumazet-glaptop> References: <1374311809-4155-1-git-send-email-freddy@asix.com.tw> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net, netdev@vger.kernel.org, grundler@google.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, louis@asix.com.tw, allan@asix.com.tw To: freddy@asix.com.tw Return-path: In-Reply-To: <1374311809-4155-1-git-send-email-freddy@asix.com.tw> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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 Thanks