From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hector Palacios Subject: Re: infinite spin in RT when booting with DHCP on Date: Thu, 2 Feb 2012 13:57:52 +0100 Message-ID: <4F2A8850.4080201@digi.com> References: <4F292FE0.7090302@digi.com> <201202021338.44950.tim.sander@hbm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "linux-rt-users@vger.kernel.org" , "lclaudio@uudg.org" , "rostedt@goodmis.org" , "efault@gmx.de" To: Tim Sander Return-path: Received: from mail37.messagelabs.com ([216.82.241.83]:29051 "EHLO mail37.messagelabs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752348Ab2BBM56 (ORCPT ); Thu, 2 Feb 2012 07:57:58 -0500 In-Reply-To: <201202021338.44950.tim.sander@hbm.com> Sender: linux-rt-users-owner@vger.kernel.org List-ID: Hello, On 02/02/2012 01:38 PM, Tim Sander wrote: > Mh, i think i am hit by the same problem. I have a i.mx 35 and when = dhcp is > enabled the ksoftirq is also running wild with 3.0-rt. This also hap= pens when > static ip is configured and the probably during network transfer the= network > interface is reconfigured. Basically it seems the sirq-net-tx thread= tries to > send a packet on a non configured interface. > > But one thing that makes me thinking, is that this thing is only hap= pening on > arm and not on x86. So Hector what platform are you working on. Are = you by > chance using the same fec.c ethernet driver? I'm working on an i.MX51 and using the fec.c driver as well. Interestin= g that it is=20 not happening on x86. > I have verified that in my case the driver takes always the return s= tatement in > line fec.c:247: return NETXDEV_TX_BUSY; > It never stops on a breakpoint set on line 250 which shows that the = interface > gets never configured. Autonegotiation is triggered by phy_state_machine() at phy.c which is s= cheduled as a=20 delayed work by phy_device.c upon PHY device creation. This is not even started when the fec_enet_start_xmit() function is cal= led. > I have taken some screenshots of my hw debugger: > >=20 trace:http://private.vlsi.informatik.tu-darmstadt.de/tstone/linux/fec_e= net_start_xmit.png >=20 stack:http://private.vlsi.informatik.tu-darmstadt.de/tstone/linux/fec_e= net_start_xmit_stacktrace.png >=20 locals:http://private.vlsi.informatik.tu-darmstadt.de/tstone/linux/fec_= enet_start_xmit_stack+locals.png > > Whats interesting to note is that phy_dev and mii_dev are both null = pointers. I'll check this but it is probably because the PHY device is not yet cr= eated or=20 initialized. Best regards, --=20 H=E9ctor Palacios -- 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