From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Fainelli Subject: Re: [PATCH net-next v2 2/3] net: dsa: integrate with SWITCHDEV for HW bridging Date: Tue, 24 Feb 2015 13:04:48 -0800 Message-ID: <54ECE770.3090608@gmail.com> References: <1424808511-18222-1-git-send-email-f.fainelli@gmail.com> <1424808511-18222-3-git-send-email-f.fainelli@gmail.com> <20150224204336.GA18025@roeck-us.net> <54ECE3DF.50503@gmail.com> <20150224205810.GA18293@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, davem@davemloft.net, vivien.didelot@savoirfairelinux.com, jerome.oufella@savoirfairelinux.com, andrew@lunn.ch, cphealy@gmail.com To: Guenter Roeck Return-path: Received: from mail-pa0-f52.google.com ([209.85.220.52]:39192 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753197AbbBXVFL (ORCPT ); Tue, 24 Feb 2015 16:05:11 -0500 Received: by pablf10 with SMTP id lf10so38909091pab.6 for ; Tue, 24 Feb 2015 13:05:11 -0800 (PST) In-Reply-To: <20150224205810.GA18293@roeck-us.net> Sender: netdev-owner@vger.kernel.org List-ID: On 24/02/15 12:58, Guenter Roeck wrote: > On Tue, Feb 24, 2015 at 12:49:35PM -0800, Florian Fainelli wrote: >> On 24/02/15 12:43, Guenter Roeck wrote: >>> Hi Florian, >>> >>> On Tue, Feb 24, 2015 at 12:08:30PM -0800, Florian Fainelli wrote: >>>> In order to support bridging offloads in DSA switch drivers, select >>>> NET_SWITCHDEV to get access to the port_stp_update and parent_get_id >>>> NDOs that we are required to implement. >>>> >>>> To facilitate the integratation at the DSA driver level, we implement 3 >>>> types of operations: >>>> >>>> - port_join_bridge >>>> - port_leave_bridge >>>> - port_stp_update >>>> >>>> DSA will resolve which switch ports that are currently bridge port >>>> members as some Switch hardware/drivers need to know about that to limit >>>> the register programming to just the relevant registers (especially for >>>> slow MDIO buses). >>>> >>>> We also take care of setting the correct STP state when slave network >>>> devices are brought up/down while being bridge members. >>>> >>>> Finally, when a port is leaving the bridge, we make sure we set in >>>> BR_STATE_FORWARDING state, otherwise the bridge layer would leave it >>>> disabled as a result of having left the bridge. >>>> >>>> Signed-off-by: Florian Fainelli >>>> --- >>> [ ... ] >>> >>>> >>>> +/* Return a bitmask of all ports being currently bridged within a given bridge >>>> + * device. Note that on leave, the mask will still return the bitmask of ports >>>> + * currently bridged, prior to port removal, and this is exactly what we want. >>>> + */ >>>> +static u32 dsa_slave_br_port_mask(struct dsa_switch *ds, >>>> + struct net_device *bridge) >>>> +{ >>>> + struct dsa_slave_priv *p; >>>> + unsigned int port; >>>> + u32 mask = 0; >>>> + >>>> + for (port = 0; port < DSA_MAX_PORTS; port++) { >>>> + if (!((1 << port) & ds->phys_port_mask)) >>>> + continue; >>>> + >>>> + p = netdev_priv(ds->ports[port]); >>>> + >>> >>> ds->ports[port] can still be NULL here since the function can be called >>> before all ports are initialized (which is what I had actually seen). >> >> Can it now? I re-ordered the patches such that your change comes first >> (and I forgot to update the commit message) and by the time we get >> called from register_netdev(), ds->ports[port] has already been assigned. >> >> Am I missing something here? > > Yes, because phys_port_mask is set to include _all_ ports, not just > the ones already registered. > > Assume ports 0..2 have been registered, phys_port_mask is 0x1f, and > dsa_slave_br_port_mask is called for a state change on port 0. > The loop will check ports 3 and 4 which have not yet been registered. Ok, I re-added the check. > > Strictly speaking we might want to consider adding the same check > into the suspend and resume functions, at least if suspend /remove > can ever happen before the system is fully initialized. Yes, that is possibly a problem, I don't think I could reproduce that with my current setup because everything needs to be built into the kernel. -- Florian