From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Schmidt Subject: Re: [PATCH 7/7] bnx2x: expose HW RX VLAN stripping toggle Date: Tue, 30 Aug 2011 21:30:11 +0200 Message-ID: <4E5D3A43.1060202@redhat.com> References: <1314714646-3642-1-git-send-email-mschmidt@redhat.com> <1314714646-3642-8-git-send-email-mschmidt@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: netdev@vger.kernel.org, vladz@broadcom.com, dmitry@broadcom.com, eilong@broadcom.com To: =?UTF-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= Return-path: Received: from mx1.redhat.com ([209.132.183.28]:6152 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754183Ab1H3TaP (ORCPT ); Tue, 30 Aug 2011 15:30:15 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On 08/30/2011 08:27 PM, Micha=C5=82 Miros=C5=82aw wrote: > It seems rather convoluted and unnecessary that you mirror > NETIF_F_HW_VLAN_RX in bp->flags This mirroring is for the benefit of functions called indirectly from=20 bnx2x_set_features(). They cannot look at dev->features for=20 NETIF_F_HW_VLAN_RX because it's not set before ->ndo_set_features() ret= urns. > and then also in fp->flags. Are the > fp->flags strictly mirroring hardware state (as in: there is no way > the states can differ in any point in time where the flags are > tested)? Yes. This is the purpose of the second mirroring of the flag. > For this to be true, the two functions above need to be > called only without releasing a lock between them that is also taken > by receive handler. The flag propagates from bp->flags to fp->flags between unloading and=20 reloading the NIC. The receive handler cannot run at the time. > Isn't there a flag in the rx descriptor of a > packet that says if VLAN was stripped? (All that flag keeping would b= e > unnecessary then.) There is no such flag, AFAIK. Michal