From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Fainelli Subject: Re: Weird DHCP related problems with net-next Date: Tue, 09 Jun 2015 13:31:31 -0700 Message-ID: <55774D23.1010508@gmail.com> References: <5577367A.50901@gmail.com> <20150609192242.GD16778@lunn.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: Netdev , Scott Feldman , Jiri Pirko To: Andrew Lunn Return-path: Received: from mail-qk0-f170.google.com ([209.85.220.170]:35345 "EHLO mail-qk0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753813AbbFIUcg (ORCPT ); Tue, 9 Jun 2015 16:32:36 -0400 Received: by qkhq76 with SMTP id q76so15037284qkh.2 for ; Tue, 09 Jun 2015 13:32:35 -0700 (PDT) In-Reply-To: <20150609192242.GD16778@lunn.ch> Sender: netdev-owner@vger.kernel.org List-ID: Hi Andrew, On 09/06/15 12:22, Andrew Lunn wrote: > On Tue, Jun 09, 2015 at 11:54:50AM -0700, Florian Fainelli wrote: >> Hi, >> >> I am observing a strange problem on net-next (not observed with net, >> bisection in progress) where the initial DHCP configuration using >> busybox's udhcpc is able to configure the local interface address and >> DNS serer, but not the default gateway. Restarting udhcpc a second time >> does not exhibit this problem. > > Hi Florian > > I've seen something similar, but different, again with DSA involved, > on a WiFi Access point. I have debian, and i'm using isc dhcp. It gets > an address, sets the address on the interface, but does not add the > interface route to the routing table. Not sure about default route, i > would have to go check that. Interesting, did you also observe this with 'net', or just with 'net-next'? Contrary to what I reported above, this is only an issue with SYSTEMPORT/DSA/SF2, I could not reproduce this GENET or the Asix driver, I was just conflating two different systems here. My bisection seems to point at this commit: 58c2cb16b116d7feace621bd6b647bbabacfa225 ("switchdev: convert fib_ipv4_add/del over to switchdev_port_obj_add/del") And indeed, hacking a bit the kernel to remove the SWITCHDEV/DSA dependencies to leave just DSA makes thing work again. Scott, Jiri, any clues? I can instrument the kernel a bit more to help find what is the problem here. Note that I am observing this on ARM (Andrew probably is as well), where uninitialized stack variables are potentially garbage. -- Florian