From mboxrd@z Thu Jan 1 00:00:00 1970 From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= Subject: Re: infinite spin in RT when booting with DHCP on Date: Thu, 2 Feb 2012 21:13:36 +0100 Message-ID: <20120202201336.GF25594@pengutronix.de> References: <4F292FE0.7090302@digi.com> <201202021338.44950.tim.sander@hbm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Hector Palacios , linux-rt-users@vger.kernel.org, lclaudio@uudg.org, rostedt@goodmis.org, efault@gmx.de To: Tim Sander Return-path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:45924 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750797Ab2BBUNo (ORCPT ); Thu, 2 Feb 2012 15:13:44 -0500 Content-Disposition: inline In-Reply-To: <201202021338.44950.tim.sander@hbm.com> Sender: linux-rt-users-owner@vger.kernel.org List-ID: Hello Tim, On Thu, Feb 02, 2012 at 01:38:44PM +0100, Tim Sander wrote: > Hi > > When booting my platform with DHCP on, the DHCP request is sent by = the > > network driver before the PHY has even started the autonegotiation. > > Since the PHY is not ready, the TX interrupt returns with NETDEV_TX= _BUSY > > but the softirq [sirq-net-tx] seems to have entered an infinite spi= n, as > > my system is practically hung and 'top' reveals [sirq-net-tx/0] is > > consuming 95% of CPU. This is preventing the PHY autonegotiation (w= hich is > > scheduled as a delayed work) to start, so the PHY is never ready an= d the > > packet never reaches the network. > Mh, i think i am hit by the same problem. I have a i.mx 35 and when d= hcp is > enabled the ksoftirq is also running wild with 3.0-rt. This also happ= ens when I fail to reproduce that on a pcm043 machine using 3.0.18-rt34. Can you provide me your config. Does the problem occur on every boot for you? I= f not, how often do I need to reboot? @Hector: Greeting to Spain. I don't have an imx51 machine handy, but your config and your answers on my questions might help, too. Best regards Uwe --=20 Pengutronix e.K. | Uwe Kleine-K=F6nig = | Industrial Linux Solutions | http://www.pengutronix.de/= | -- To unsubscribe from this list: send the line "unsubscribe linux-rt-user= s" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html