From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: [PATCH 3/5] e1000e: Allow TSO to trickle down to VLAN device Date: Wed, 30 Apr 2008 08:54:37 +0200 Message-ID: <481817AD.1010306@trash.net> References: <20080414170557.23286.71580.stgit@localhost.localdomain> <20080414170609.23286.42880.stgit@localhost.localdomain> <4803903B.1020100@trash.net> <4807C516.90308@intel.com> <480CA399.50708@trash.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: e1000-devel@lists.sourceforge.net, netdev@vger.kernel.org, "Kok, Auke-jan H" , jeff@garzik.org To: "Waskiewicz Jr, Peter P" Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: e1000-devel-bounces@lists.sourceforge.net Errors-To: e1000-devel-bounces@lists.sourceforge.net List-Id: netdev.vger.kernel.org Waskiewicz Jr, Peter P wrote: >> In any case I would prefer to avoid having drivers mess with VLAN >> device flags. How about adding a device flag indicating that the >> driver supports TSO + VLAN acceleration and using the >> NETDEV_FEAT_CHANGE notification inside the VLAN code do adjust >> the device's flags properly? > > I've been looking into this, and I agree this makes sense when creating > a new VLAN to get the device flags to the VLAN device. However, we need > to get the TSO and/or Tx checksum offload feature flags off all VLAN > devices when the parent device has it turned off. I don't see any clean > way of doing this with netdev_features_change(). I'd really love to > implement this correctly, so if you have any ideas on how to handle this > latter case, I'm all ears. :-) Whats the problem with doing: - on VLAN creation: copy VLAN flag from lower device if lowerdev has NETIF_F_ - on change of TSO/checksumming flags of lower device: use netdevice notifier to adjust the settings for all VLANs on that device ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone