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 spin, as > my system is practically hung and 'top' reveals [sirq-net-tx/0] is > consuming 95% of CPU. This is preventing the PHY autonegotiation (which is > scheduled as a delayed work) to start, so the PHY is never ready and the > packet never reaches the network. 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 happens 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 happening 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 have verified that in my case the driver takes always the return statement 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. I have taken some screenshots of my hw debugger: trace:http://private.vlsi.informatik.tu-darmstadt.de/tstone/linux/fec_enet_start_xmit.png stack:http://private.vlsi.informatik.tu-darmstadt.de/tstone/linux/fec_enet_start_xmit_stacktrace.png 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. Best regards Tim Hottinger Baldwin Messtechnik GmbH, Im Tiefen See 45, 64293 Darmstadt, Germany | www.hbm.com Registered as GmbH (German limited liability corporation) in the commercial register at the local court of Darmstadt, HRB 1147 Company domiciled in Darmstadt | CEO: Andreas Huellhorst | Chairman of the board: James Charles Webster Als Gesellschaft mit beschraenkter Haftung eingetragen im Handelsregister des Amtsgerichts Darmstadt unter HRB 1147 Sitz der Gesellschaft: Darmstadt | Geschaeftsfuehrung: Andreas Huellhorst | Aufsichtsratsvorsitzender: James Charles Webster The information in this email is confidential. It is intended solely for the addressee. If you are not the intended recipient, please let me know and delete this email. Die in dieser E-Mail enthaltene Information ist vertraulich und lediglich für den Empfaenger bestimmt. Sollten Sie nicht der eigentliche Empfaenger sein, informieren Sie mich bitte kurz und loeschen diese E-Mail. -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
