<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi all,<br><br>We are several Openwrt users based on the TPlink 4900 device and suffer from a crashing gianfar driver.<br>We troubleshooted the problem down to the fact, that a 3.8er Linux kernel is working, and a v3.10 crashes, but there is<br>no reproducable case yet. The driver crashes after a couple of minutes but this can not be triggered by high network load, or routing traffic.<br>I recorded the crash via a serial line and did a gdb lookup in gainfar.c<br>All infos and logs we collected so far in the OpenWRt forum:<a href="https://forum.openwrt.org/viewtopic.php?pid=213901#p213901">https://forum.openwrt.org/viewtopic.php?pid=213901#p213901</a><br><br>Here is my last troubleshooting log on the openwrt mailing list<br><br>I just hooked up a serial line to my tplinl4900. Used a recent trunk image and could catch the output of the crash.<br>The problem comes from the ethernet driver gfar<br><br>[code]<br>[ 2671.841927] Oops: Exception in kernel mode, sig: 5 [#1]<br>[ 2671.847141] Freescale P1014<br>[ 2671.849925] Modules linked in: ath9k pppoe ppp_async iptable_nat ath9k_common pppox p<br>e xt_tcpudp xt_tcpmss xt_string xt_statistic xt_state xt_recent xt_quota xt_pkttype xt_o<br>mark xt_connbytes xt_comment xt_addrtype xt_TCPMSS xt_REDIRECT xt_NETMAP xt_LOG xt_IPMAR<br>ms_datafab ums_cypress ums_alauda slhc nf_nat_tftp nf_nat_snmp_basic nf_nat_sip nf_nat_r<br>ntrack_sip nf_conntrack_rtsp nf_conntrack_proto_gre nf_conntrack_irc nf_conntrack_h323 n<br>compat_xtables compat ath sch_teql sch_tbf sch_sfq sch_red sch_prio sch_htb sch_gred sc<br>skbedit act_mirred em_u32 cls_u32 cls_tcindex cls_flow cls_route cls_fw sch_hfsc sch_ing<br>r usb_storage leds_gpio ohci_hcd ehci_platform ehci_hcd sd_mod scsi_mod fsl_mph_dr_of gp<br>[ 2671.988946] CPU: 0 PID: 5209 Comm: iftop Not tainted 3.10.13 #2<br>[ 2671.994859] task: c4b22220 ti: c7ff8000 task.ti: c477e000<br>[ 2672.000250] NIP: c018c7a0 LR: c018c794 CTR: c000b070<br>[ 2672.005206] REGS: c7ff9f10 TRAP: 3202 Not tainted (3.10.13)<br>[ 2672.011028] MSR: 00029000 <CE,EE,ME> CR: 48000024 XER: 20000000<br>[ 2672.017125] <br>GPR00: 000000ff c477fde0 c4b22220 00000000 00000000 000000ff 00000000 70000000 <br>GPR08: ffffffff 00000008 00000000 ffffffff 00000046 10022248 00000000 00000008 <br>GPR16: c781b3c0 c781b3c0 000000ff 00000000 00000001 0000021c 00000086 fffff800 <br>GPR24: c7980300 00000000 00000001 00000040 00000003 c4b33000 00000000 00000001 <br>[ 2672.046832] NIP [c018c7a0] gfar_poll+0x424/0x520<br>[ 2672.051442] LR [c018c794] gfar_poll+0x418/0x520<br>[ 2672.055962] Call Trace:<br>[ 2672.058402] [c477fde0] [c018c674] gfar_poll+0x2f8/0x520 (unreliable)<br>[ 2672.064762] [c477fe80] [c01b0ce8] net_rx_action+0x6c/0x158<br>[ 2672.070249] [c477feb0] [c0027dc4] __do_softirq+0xbc/0x16c<br>[ 2672.075642] [c477ff00] [c0027f7c] irq_exit+0x4c/0x68<br>[ 2672.080604] [c477ff10] [c00041f8] do_IRQ+0xf4/0x10c<br>[ 2672.085478] [c477ff40] [c000ca3c] ret_from_except+0x0/0x18<br>[ 2672.090991] --- Exception: 501 at 0x48083c28<br>[ 2672.090991] LR = 0x48083bf8<br>[ 2672.098378] Instruction dump:<br>[ 2672.101338] 7f8f2040 419cfcc4 80900000 38a00000 8061004c 7e118378 81c10050 7ffafb78 <br>[ 2672.109092] 4bf9eaa1 83810034 7c7e1b78 8361003c <83210038> 83a1004c 48000060 41a2004c<br>[ 2672.117021] ---[ end trace 565fb54528d305fa ]---<br>[ 2672.121628] <br>[ 2673.103130] Kernel panic - not syncing: Fatal exception in interrupt<br>[ 2673.109474] Rebooting in 3 seconds..<br><br>U-Boot 2010.12-svn15934 (Dec 11 2012 - 16:23:49)<br>[/code]<br><br><br>A cross-gdb lookup to gianfar.o shows that the problem appier in function "gfar_poll"<br><br>[code]<br>./gdb ../../../target-powerpc_uClibc-0.9.33.2/linux-mpc85xx_generic/linux-3.10.12/drivers/net/ethernet/freescale/gianfar.o<br><br>This GDB was configured as "--host=x86_64-linux-gnu --target=powerpc-openwrt-linux-uclibcspe".<br>For bug reporting instructions, please see:<br><[url]<a href="http://bugs.launchpad.net/gdb-linaro/[/url]">http://bugs.launchpad.net/gdb-linaro/[/url]</a>>...<br>Reading symbols from /home/thomas/BB-evernet/build_dir/target-powerpc_uClibc-0.9.33.2/linux-mpc85xx_generic/linux-3.10.12/drivers/net/ethernet/freescale/gianfar.o...done.<br>(gdb) l *gfar_poll+0x2f8/0x520<br>0x4538 is in gfar_poll (drivers/net/ethernet/freescale/gianfar.c:2829).<br>2824<br>2825 return howmany;<br>2826 }<br>2827<br>2828 static int gfar_poll(struct napi_struct *napi, int budget)<br>2829 {<br>2830 struct gfar_priv_grp *gfargrp =<br>2831 container_of(napi, struct gfar_priv_grp, napi);<br>2832 struct gfar_private *priv = gfargrp->priv;<br>2833 struct gfar __iomem *regs = gfargrp->regs;<br>(gdb) q<br><br>[/code]<br><br><br>The changes from Linux kernel 3.8, which seems to have proper working ehternet, to the current 3.10 seem to intruduce a bug in the GIANFAR driver: drivers/net/ethernet/freescale/gianfra.c<br>There were different changes in the NAPI of gianfar driver made between the two kernel versions. <br>Please let us know which next troubleshooting step you would recommend to nail down the issue.<br><br>So far from troubleshooting.<br><br>Greetings Thomas</body></html>