So after 3 days the issue reappeared. At time of failure SNR was below 6dB, looks like a line issue problem, not sure why a reboot fixes it.
# date -u
Fri Jul 20 11:48:29 UTC 2018
# /etc/init.d/dsl_control status
ATU-C Vendor ID: Infineon 113.185
ATU-C System Vendor ID: 00,00,00,00,00,00,00,00
Chipset: Ifx-AR9
Firmware Version: 4.4.4.0.0.1
API Version: 3.24.4.4
XTSE Capabilities: 0x0, 0x0, 0x0, 0x0, 0x0, 0x1, 0x0, 0x0
Annex: A
Line Mode: G.992.5 (ADSL2+)
Profile:
Line State: UP [0x801: showtime_tc_sync]
Forward Error Correction Seconds (FECS): Near: 1173920 / Far: 40352
Errored seconds (ES): Near: 950 / Far: 207
Severely Errored Seconds (SES): Near: 45 / Far: 0
Loss of Signal Seconds (LOSS): Near: 6 / Far: 3
Unavailable Seconds (UAS): Near: 296 / Far: 296
Header Error Code Errors (HEC): Near: 37986 / Far: 294
Non Pre-emtive CRC errors (CRC_P): Near: / Far:
Pre-emtive CRC errors (CRCP_P): Near: / Far:
Power Management Mode: L0 - Synchronized
Latency [Interleave Delay]: 7.0 ms [Interleave] 1.25 ms [Interleave]
Data Rate: Down: 18.733 Mb/s / Up: 1.020 Mb/s
Line Attenuation (LATN): Down: 16.8 dB / Up: 8.8 dB
Signal Attenuation (SATN): Down: 15.7 dB / Up: 9.5 dB
Noise Margin (SNR): Down: 6.0 dB / Up: 12.1 dB
Aggregate Transmit Power (ACTATP): Down: 16.3 dB / Up: 11.8 dB
Max. Attainable Data Rate (ATTNDR): Down: 18.600 Mb/s / Up: 1.220 Mb/s
Line Uptime Seconds: 261796
Line Uptime: 3d 0h 43m 16s
[ 90.209608] enter showtime, cell rate: 0 - 2407, 1 - 2407, xdata addr: 0x82dc0000
[ 96.517572] pppoe-wan: renamed from ppp0
[22758.493805] leave showtime
[22942.647217] [DSL_BSP_Showtime 914]: Datarate US intl = 1020958, fast = 0
[22942.652600] enter showtime, cell rate: 0 - 2407, 1 - 2407, xdata addr: 0x82da0000
[22958.548761] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[22959.019453] pppoe-wan: renamed from ppp0
[23065.959287] leave showtime
[23132.250299] [DSL_BSP_Showtime 914]: Datarate US intl = 1020958, fast = 0
[23132.255640] enter showtime, cell rate: 0 - 2407, 1 - 2407, xdata addr: 0x82e70000
[23142.989191] pppoe-wan: renamed from ppp0
[52065.642905] ath: phy0: DMA failed to stop in 10 ms AR_CR=0x00000024 AR_DIAG_SW=0x42100020 DMADBG_7=0x000084c0
[290866.503156] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[290882.118626] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[290897.719175] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[290913.324659] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[290928.927151] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[290944.546290] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[290960.155969] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[290975.765655] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[290991.376855] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291007.200907] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291023.385175] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291039.541801] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291056.120393] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291073.211340] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291090.039997] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291105.663043] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291121.262970] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291136.902193] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291152.516178] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291168.117564] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291183.721892] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291199.350719] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291214.950276] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291230.594298] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291246.189149] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291261.825799] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291277.427613] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291293.077220] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291308.681204] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291324.311522] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291339.919222] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291355.524601] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
[291371.116324] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
Fri Jul 20 21:44:45 2018 daemon.warn pppd[9969]: Timeout waiting for PADO packets
Fri Jul 20 21:44:45 2018 daemon.err pppd[9969]: Unable to complete PPPoE Discovery
Fri Jul 20 21:44:45 2018 daemon.info pppd[9969]: Exit.
Fri Jul 20 21:44:46 2018 daemon.notice netifd: Interface 'wan' is now down
Fri Jul 20 21:44:46 2018 kern.info kernel: [291230.594298] IPv6: ADDRCONF(NETDEV_UP): dsl0: link is not ready
Fri Jul 20 21:44:46 2018 daemon.notice netifd: Interface 'wan' is disabled
Fri Jul 20 21:44:46 2018 daemon.notice netifd: Interface 'wan' is enabled
Fri Jul 20 21:44:46 2018 daemon.notice netifd: Interface 'wan' is setting up now
Fri Jul 20 21:44:46 2018 daemon.err insmod: module is already loaded - slhc
Fri Jul 20 21:44:46 2018 daemon.err insmod: module is already loaded - ppp_generic
Fri Jul 20 21:44:46 2018 daemon.err insmod: module is already loaded - pppox
Fri Jul 20 21:44:46 2018 daemon.err insmod: module is already loaded - pppoe
Fri Jul 20 21:44:46 2018 daemon.info pppd[10022]: Plugin rp-pppoe.so loaded.
Fri Jul 20 21:44:46 2018 daemon.info pppd[10022]: RP-PPPoE plugin version 3.8p compiled against pppd 2.4.7
Fri Jul 20 21:44:46 2018 daemon.notice pppd[10022]: pppd 2.4.7 started by root, uid 0
Fri Jul 20 21:45:01 2018 daemon.warn pppd[10022]: Timeout waiting for PADO packets
====After Reboot====
# /etc/init.d/dsl_control status
ATU-C Vendor ID: Infineon 113.185
ATU-C System Vendor ID: 00,00,00,00,00,00,00,00
Chipset: Ifx-AR9
Firmware Version: 4.4.4.0.0.1
API Version: 3.24.4.4
XTSE Capabilities: 0x0, 0x0, 0x0, 0x0, 0x0, 0x1, 0x0, 0x0
Annex: A
Line Mode: G.992.5 (ADSL2+)
Profile:
Line State: UP [0x801: showtime_tc_sync]
Forward Error Correction Seconds (FECS): Near: 93 / Far: 0
Errored seconds (ES): Near: 0 / Far: 0
Severely Errored Seconds (SES): Near: 0 / Far: 0
Loss of Signal Seconds (LOSS): Near: 0 / Far: 2
Unavailable Seconds (UAS): Near: 46 / Far: 46
Header Error Code Errors (HEC): Near: 0 / Far: 7
Non Pre-emtive CRC errors (CRC_P): Near: / Far:
Pre-emtive CRC errors (CRCP_P): Near: / Far:
Power Management Mode: L0 - Synchronized
Latency [Interleave Delay]: 7.0 ms [Interleave] 1.25 ms [Interleave]
Data Rate: Down: 18.702 Mb/s / Up: 1.020 Mb/s
Line Attenuation (LATN): Down: 16.8 dB / Up: 8.8 dB
Signal Attenuation (SATN): Down: 16.0 dB / Up: 9.2 dB
Noise Margin (SNR): Down: 6.0 dB / Up: 11.3 dB
Aggregate Transmit Power (ACTATP): Down: 16.3 dB / Up: 11.3 dB
Max. Attainable Data Rate (ATTNDR): Down: 18.696 Mb/s / Up: 1.192 Mb/s
Line Uptime Seconds: 21
Line Uptime: 21s