[FS#494] NETDEV WATCHDOG: ptm0 (): transmit queue 0 timed out

[LEDE Bugs]

A new Flyspray task has been opened.  Details are below. 

User who did this - Martin Dindos (dziny) 

Attached to Project - LEDE Project
Summary - NETDEV WATCHDOG: ptm0 (): transmit queue 0 timed out
Task Type - Bug Report
Category - Base system
Status - Unconfirmed
Assigned To - 
Operating System - All
Severity - Critical
Priority - Very Low
Reported Version - All
Due in Version - Undecided
Due Date - Undecided
Details - I have a VDSL line with Plusnet (UK) - the connection is pppoe - ptm0.101. With the supplied modem/router the line and connection is stable with no disconnects. With LEDE the connection is established and works well until it disconnects (sometimes as early as few minutes other times it stays connected up to an hour). After the disconnect there is no reconnection until a reboot. Restarting wan interface (ifdown wan/ifup wan) or dsl connection (/etc/init.d/dslcontrol stop/start) does not help. 

Supply the following if possible:
 - Device problem occurs on   TP-w8970 and BTHomehub 5A (same crash on both lantiq based devices)
 - Software versions of LEDE release, packages, etc.  Tested on LEDE RC2, earlier LEDE snapshot from October 2016, Openwrt CC - same symptoms
 - Steps to reproduce - VDSL connection on ptm0.101 via pppoe

Here is a trace of the crash (dmesg):

[ 1414.124413] ---[ beginning trace ff034b465cdad16b ]---
[ 1414.125631] WARNING: CPU: 0 PID: 0 at net/sched/sch_generic.c:303 dev_watchdog+0x1a8/0x2f0()
[ 1414.126471] NETDEV WATCHDOG: ptm0 (): transmit queue 0 timed out
[ 1414.132456] Modules linked in: ltq_ptm_vr9 option iptable_nat ath9k usb_wwan rt2800usb rt2800lib 
pppoe nf_nat_ipv4 nf_conntrack_ipv6 nf_conntrack_ipv4 l2tp_ppp ipt_REJECT ipt_MASQUERADE ath9k_common 
xt_time xt_tcpudp xt_tcpmss xt_statistic xt_state xt_recent xt_policy xt_nat xt_multiport xt_mark xt_mac 
xt_limit xt_length xt_id xt_hl xt_helper xt_esp xt_ecn xt_dscp xt_conntrack xt_connmark xt_connlimit 
xt_connbytes xt_comment xt_TCPMSS xt_REDIRECT xt_LOG xt_HL xt_DSCP xt_CT xt_CLASSIFY usbserial rt2x00usb 
rt2x00lib pppox ppp_async nf_reject_ipv4 nf_nat_redirect nf_nat_masquerade_ipv4 nf_nat nf_log_ipv4 nf_defrag_ipv6 
nf_defrag_ipv4 nf_conntrack_rtcache nf_conntrack ltq_deu_vr9 iptable_raw iptable_mangle iptable_filter ipt_ah ipt_ECN 
ip_tables crc_itu_t crc_ccitt cdc_acm ath9k_hw ath10k_pci ath10k_core ath mac80211 cfg80211 compat drv_dsl_cpe_api 
drv_mei_cpe xt_set ip_set_list_set ip_set_hash_netiface ip_set_hash_netport ip_set_hash_netnet ip_set_hash_net 
ip_set_hash_netportnet ip_set_hash_mac ip_set_hash_ipportnet ip_set_hash_ipportip ip_set_hash_ipport ip_set_hash_ipmark 
ip_set_hash_ip ip_set_bitmap_port ip_set_bitmap_ipmac ip_set_bitmap_ip ip_set nfnetlink ip6t_REJECT nf_reject_ipv6 
nf_log_ipv6 nf_log_common ip6table_raw ip6table_mangle ip6table_filter ip6_tables x_tables pppoatm ppp_generic slhc 
l2tp_ip6 l2tp_ip l2tp_eth sit l2tp_netlink l2tp_core udp_tunnel ip6_udp_tunnel ipcomp xfrm4_tunnel xfrm4_mode_tunnel 
xfrm4_mode_transport xfrm4_mode_beet esp4 ah4 tunnel4 ip_tunnel tun af_key xfrm_user xfrm_ipcomp xfrm_algo br2684 atm 
drv_ifxos echainiv sha256_generic sha1_generic jitterentropy_rng drbg md5 hmac des_generic cbc authenc usb_storage
dwc2 uhci_hcd ehci_platform ehci_hcd sd_mod scsi_mod gpio_button_hotplug ext4 jbd2 mbcache aead crypto_null
[ 1414.287462] CPU: 0 PID: 0 Comm: swapper Not tainted 4.4.7 #1
[ 1414.293130] Stack : 804b0000 00000001 00000000 00000000 805172b8 80516f43 80489a24 00000000
[ 1414.293130]    80673844 00010000 80510000 805159bc 80515abc 80055664 00000003 80510000
[ 1414.293130]    80491b4c 00000000 8048ff50 80511c44 80515abc 800535b0 00000006 00000001
[ 1414.293130]    00000000 80512000 00000000 00000000 00000000 00000000 00000000 00000000
[ 1414.293130]    00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 1414.293130]    ...
[ 1414.328618] Call Trace:
[ 1414.331095] [] show_stack+0x50/0x84
[ 1414.335454] [] warn_slowpath_common+0xa0/0xd0
[ 1414.340670] [] warn_slowpath_fmt+0x2c/0x38
[ 1414.345636] [] dev_watchdog+0x1a8/0x2f0
[ 1414.350348] [] call_timer_fn.isra.5+0x24/0x80
[ 1414.355557] [] run_timer_softirq+0x1a4/0x208
[ 1414.360694] [] __do_softirq+0x298/0x2b0
[ 1414.365388] [] ret_from_irq+0x0/0x4
[ 1414.369760] [] r4k_wait_irqoff+0x18/0x20
[ 1414.374528] [] cpu_startup_entry+0xa4/0xf8
[ 1414.379508] [] start_kernel+0x474/0x494
[ 1414.384180]
[ 1414.385631] ---[ end trace ff034b465cdad16b ]---
   

 

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=494