From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alban Subject: Re: [PATCH 1/2] 8139too: Allow setting MTU larger than 1500 Date: Fri, 21 Nov 2014 14:58:53 +0100 Message-ID: <20141121145853.1be898de@tock> References: <1415447316-12424-1-git-send-email-albeu@free.fr> <1416530074.7215.11.camel@decadent.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Aban Bedel , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Bjorn Helgaas , Benoit Taine , "Eric W. Biederman" , "David S. Miller" To: Ben Hutchings Return-path: In-Reply-To: <1416530074.7215.11.camel@decadent.org.uk> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Fri, 21 Nov 2014 00:34:34 +0000 Ben Hutchings wrote: > On Sat, 2014-11-08 at 12:48 +0100, Alban Bedel wrote: > > Replace the default ndo_change_mtu callback with one that allow > > setting MTU that the driver can handle. > > > > Signed-off-by: Alban Bedel > > --- > > drivers/net/ethernet/realtek/8139too.c | 13 ++++++++++++- > > 1 file changed, 12 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/net/ethernet/realtek/8139too.c > > b/drivers/net/ethernet/realtek/8139too.c index 007b38c..8387de9 > > 100644 --- a/drivers/net/ethernet/realtek/8139too.c > > +++ b/drivers/net/ethernet/realtek/8139too.c > > @@ -185,6 +185,9 @@ static int debug = -1; > > /* max supported ethernet frame size -- must be at least > > (dev->mtu+14+4).*/ #define MAX_ETH_FRAME_SIZE 1536 > > > > +/* max supported payload size */ > > +#define MAX_ETH_DATA_SIZE (MAX_ETH_FRAME_SIZE - ETH_HLEN - > > ETH_FCS_LEN) > [...] > > Does this maximum still allow for VLAN tags, or should it use > VLAN_ETH_HLEN instead of ETH_HLEN? That might well be as the VLAN code seems to assume that the physical device can handle frames of MTU + VLAN_HLEN bytes. I can fix it, but to me it seems like the VLAN code should be fixed to respect the physical device MTU. Alban