[Solved] BT Home Hub 5A: LEDE 17.01.4 WAN ADSL PPoA does not work (tiscali.it)

Hi,
I just bought an BT Home Hub 5A with preinstalled firmware version LEDE Reboot 17.01.4 r3560-79f57e422d / LuCI lede-17.01 branch (git-17.290.79498-d3f0685) and kernel version 4.4.92.
I have a problem about configuring my WAN interface for ADSL2+. The parameters of my provider are the following:
VPI 8
VCI 35
Protocol PPP over ATM (RCF 2364)
Encapsulation VC-Multiplexing (VC-MUX)
I think that I correclty configured the LEDE, but I get the following error in system.log file:

Sun May  6 08:12:47 2018 daemon.err pppd[22132]: connect(0.8.35): No such device

The previous router/modem TP-Link W9980 worked well with the same parameters.

Links with screenshot of my WAN configuration:


kernel.log file

[    0.000000] Linux version 4.4.92 (buildbot@debian8) (gcc version 5.4.0 (LEDE GCC 5.4.0 r3560-79f57e422d) ) #0 Tue Oct 17 17:46:20 2017
[    0.000000] SoC: xRX200 rev 1.2
[    0.000000] bootconsole [early0] enabled
[    0.000000] CPU0 revision is: 00019556 (MIPS 34Kc)
[    0.000000] MIPS: machine is BTHOMEHUBV5A - BT Home Hub 5A
[    0.000000] Determined physical RAM map:
[    0.000000]  memory: 08000000 @ 00000000 (usable)
[    0.000000] Initrd not found or empty - disabling initrd
[    0.000000] Zone ranges:
[    0.000000]   Normal   [mem 0x0000000000000000-0x0000000007ffffff]
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000000000000-0x0000000007ffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x0000000007ffffff]
[    0.000000] On node 0 totalpages: 32768
[    0.000000] free_area_init_node: node 0, pgdat 804bc4b0, node_mem_map 81009520
[    0.000000]   Normal zone: 256 pages used for memmap
[    0.000000]   Normal zone: 0 pages reserved
[    0.000000]   Normal zone: 32768 pages, LIFO batch:7
[    0.000000] Primary instruction cache 32kB, VIPT, 4-way, linesize 32 bytes.
[    0.000000] Primary data cache 32kB, 4-way, VIPT, cache aliases, linesize 32 bytes
[    0.000000] pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768
[    0.000000] pcpu-alloc: [0] 0 
[    0.000000] Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 32512
[    0.000000] Kernel command line: console=ttyLTQ0,115200
[    0.000000] PID hash table entries: 512 (order: -1, 2048 bytes)
[    0.000000] Dentry cache hash table entries: 16384 (order: 4, 65536 bytes)
[    0.000000] Inode-cache hash table entries: 8192 (order: 3, 32768 bytes)
[    0.000000] Writing ErrCtl register=0002d901
[    0.000000] Readback ErrCtl register=0002d901
[    0.000000] Memory: 123408K/131072K available (3923K kernel code, 161K rwdata, 884K rodata, 1224K init, 213K bss, 7664K reserved, 0K cma-reserved)
[    0.000000] SLUB: HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[    0.000000] NR_IRQS:256
[    0.000000] Setting up vectored interrupts
[    0.000000] CPU Clock: 500MHz
[    0.000000] clocksource: MIPS: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645041786 ns
[    0.000010] sched_clock: 32 bits at 250MHz, resolution 4ns, wraps every 8589934590ns
[    0.007856] Calibrating delay loop... 332.54 BogoMIPS (lpj=665088)
[    0.042316] pid_max: default: 32768 minimum: 301
[    0.047158] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
[    0.053722] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
[    0.066623] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645041785100000 ns
[    0.076266] futex hash table entries: 256 (order: -1, 3072 bytes)
[    0.082478] pinctrl core: initialized pinctrl subsystem
[    0.088986] NET: Registered protocol family 16
[    0.097804] pinctrl-xway 1e100b10.pinmux: Init done
[    0.103317] dma-xway 1e104100.dma: Init done - hw rev: 7, ports: 7, channels: 28
[    0.213176] dcdc-xrx200 1f106a00.dcdc: Core Voltage : 1016 mV
[    0.218917] Can't analyze schedule() prologue at 80009078
[    0.232780] PCI host bridge /fpi@10000000/pci@E105400 ranges:
[    0.238394]  MEM 0x0000000018000000..0x0000000019ffffff
[    0.243679]   IO 0x000000001ae00000..0x000000001affffff
[    0.366605] PCI host bridge /fpi@10000000/pcie@d900000 ranges:
[    0.386060] usbcore: registered new interface driver usbfs
[    0.391544] usbcore: registered new interface driver hub
[    0.396903] usbcore: registered new device driver usb
[    0.402309] PCI host bridge to bus 0000:00
[    0.406303] pci_bus 0000:00: root bus resource [mem 0x18000000-0x19ffffff]
[    0.413209] pci_bus 0000:00: root bus resource [io  0x1ae00000-0x1affffff]
[    0.420153] pci_bus 0000:00: root bus resource [??? 0x00000000 flags 0x0]
[    0.427009] pci_bus 0000:00: No busn resource found for root bus, will use [bus 00-ff]
[    0.435058] pci 0000:00:0e.0: [168c:ff1d] type 00 class 0x020000
[    0.435117] pci 0000:00:0e.0: reg 0x10: [mem 0x00000000-0x0000ffff]
[    0.435480] pci_bus 0000:00: busn_res: [bus 00-ff] end is updated to 00
[    0.435521] pci 0000:00:0e.0: BAR 0: assigned [mem 0x18000000-0x1800ffff]
[    0.442384] PCI host bridge to bus 0000:01
[    0.446374] pci_bus 0000:01: root bus resource [mem 0x1c000000-0x1cffffff]
[    0.453289] pci_bus 0000:01: root bus resource [io  0x1d800000-0x1d8fffff]
[    0.460230] pci_bus 0000:01: root bus resource [??? 0x00000000 flags 0x0]
[    0.467085] pci_bus 0000:01: No busn resource found for root bus, will use [bus 01-ff]
[    0.475114] pci 0000:01:00.0: [1bef:0011] type 01 class 0x060000
[    0.475149] ifx_pcie_rc_class_early_fixup: fixed pcie host bridge to pci-pci bridge
[    0.492897] pci 0000:01:00.0: PME# supported from D0 D3hot
[    0.493204] pci 0000:01:00.0: bridge configuration invalid ([bus 02-00]), reconfiguring
[    0.501333] pci 0000:02:00.0: [168c:003c] type 00 class 0x028000
[    0.501421] pci 0000:02:00.0: reg 0x10: [mem 0x00000000-0x001fffff 64bit]
[    0.501490] pci 0000:02:00.0: reg 0x30: [mem 0x00000000-0x0000ffff pref]
[    0.501594] pci 0000:02:00.0: supports D1 D2
[    0.501876] pci_bus 0000:02: busn_res: [bus 02-ff] end is updated to 02
[    0.501914] pci_bus 0000:01: busn_res: [bus 01-ff] end is updated to 02
[    0.501966] pci 0000:01:00.0: BAR 8: assigned [mem 0x1c000000-0x1c1fffff]
[    0.508643] pci 0000:01:00.0: BAR 9: assigned [mem 0x1c200000-0x1c2fffff pref]
[    0.515910] pci 0000:02:00.0: BAR 0: assigned [mem 0x1c000000-0x1c1fffff 64bit]
[    0.523309] pci 0000:02:00.0: BAR 6: assigned [mem 0x1c200000-0x1c20ffff pref]
[    0.530572] pci 0000:01:00.0: PCI bridge to [bus 02]
[    0.535609] pci 0000:01:00.0:   bridge window [mem 0x1c000000-0x1c1fffff]
[    0.542465] pci 0000:01:00.0:   bridge window [mem 0x1c200000-0x1c2fffff pref]
[    0.549834] ifx_pcie_bios_map_irq port 0 dev 0000:01:00.0 slot 0 pin 1 
[    0.556440] ifx_pcie_bios_map_irq dev 0000:01:00.0 irq 144 assigned
[    0.562783] ifx_pcie_bios_map_irq port 0 dev 0000:02:00.0 slot 0 pin 1 
[    0.569449] ifx_pcie_bios_map_irq dev 0000:02:00.0 irq 144 assigned
[    0.576656] clocksource: Switched to clocksource MIPS
[    0.582863] NET: Registered protocol family 2
[    0.588139] TCP established hash table entries: 1024 (order: 0, 4096 bytes)
[    0.595026] TCP bind hash table entries: 1024 (order: 0, 4096 bytes)
[    0.601402] TCP: Hash tables configured (established 1024 bind 1024)
[    0.607907] UDP hash table entries: 256 (order: 0, 4096 bytes)
[    0.613764] UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)
[    0.620303] NET: Registered protocol family 1
[    0.624629] PCI: CLS 0 bytes, default 32
[    0.631652] gptu: totally 6 16-bit timers/counters
[    0.636479] gptu: misc_register on minor 63
[    0.640583] gptu: succeeded to request irq 126
[    0.645072] gptu: succeeded to request irq 127
[    0.649589] gptu: succeeded to request irq 128
[    0.654098] gptu: succeeded to request irq 129
[    0.658611] gptu: succeeded to request irq 130
[    0.663125] gptu: succeeded to request irq 131
[    0.667951] phy-xrx200 gphy-xrx200: requesting lantiq/vr9_phy11g_a2x.bin
[    0.675202] phy-xrx200 gphy-xrx200: booting GPHY0 firmware at 7DA0000
[    0.681536] phy-xrx200 gphy-xrx200: booting GPHY1 firmware at 7DA0000
[    0.788163] No VPEs reserved for AP/SP, not initialize VPE loader
[    0.788163] Pass maxvpes=<n> argument as kernel argument
[    0.799513] No TCs reserved for AP/SP, not initializing RTLX.
[    0.799513] Pass maxtcs=<n> argument as kernel argument
[    0.811335] Crashlog allocated RAM at address 0x3f00000
[    0.836701] squashfs: version 4.0 (2009/01/31) Phillip Lougher
[    0.842387] jffs2: version 2.2 (NAND) (SUMMARY) (LZMA) (RTIME) (CMODE_PRIORITY) (c) 2001-2006 Red Hat, Inc.
[    0.856120] io scheduler noop registered
[    0.859931] io scheduler deadline registered (default)
[    0.865796] 1e100c00.serial: ttyLTQ0 at MMIO 0x1e100c00 (irq = 112, base_baud = 0) is a lantiq,asc
[    0.874695] console [ttyLTQ0] enabled
[    0.882022] bootconsole [early0] disabled
[    0.891177] nand: device found, Manufacturer ID: 0xec, Chip ID: 0xf1
[    0.896070] nand: Samsung NAND 128MiB 3,3V 8-bit
[    0.900685] nand: 128 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64
[    0.910928] Bad block table found at page 65472, version 0x01
[    0.915908] Bad block table found at page 65408, version 0x01
[    0.921094] nand_read_bbt: bad block at 0x000004a00000
[    0.926232] 4 ofpart partitions found on MTD device 14000000.nand-parts
[    0.932751] Creating 4 MTD partitions on "14000000.nand-parts":
[    0.938655] 0x000000000000-0x0000000a0000 : "u-boot"
[    0.945440] 0x0000000a0000-0x0000000c0000 : "uboot-env"
[    0.951272] 0x0000000c0000-0x000000100000 : "unused"
[    0.956919] 0x000000100000-0x000007f80000 : "ubi"
[    1.065307] libphy: lantiq,xrx200-mdio: probed
[    1.077034] net-xrx200: invalid MAC, using random
[    1.141389] eth0: attached PHY [Lantiq XWAY PEF7071] (phy_addr=0:00, irq=-1)
[    1.209362] eth0: attached PHY [Lantiq XWAY PEF7071] (phy_addr=0:01, irq=-1)
[    1.277348] eth0: attached PHY [Lantiq XWAY VR9 GPHY 11G v1.4] (phy_addr=0:11, irq=-1)
[    1.345347] eth0: attached PHY [Lantiq XWAY VR9 GPHY 11G v1.4] (phy_addr=0:13, irq=-1)
[    1.413363] eth0: attached PHY [Lantiq XWAY PEF7071] (phy_addr=0:05, irq=-1)
[    1.520617] ltq-cputemp cputemp@0: Current CPU die temperature: 58.5 °C
[    1.526157] wdt 1f8803f0.watchdog: Init done
[    1.533560] NET: Registered protocol family 10
[    1.542621] NET: Registered protocol family 17
[    1.545763] bridge: automatic filtering via arp/ip/ip6tables has been deprecated. Update your scripts to load br_netfilter if you need this.
[    1.558277] 8021q: 802.1Q VLAN Support v1.8
[    1.566570] UBI: auto-attach mtd3
[    1.568251] ubi0: attaching mtd3
[    1.754551] ubi0: scanning is finished
[    1.769235] ubi0: attached mtd3 (name "ubi", size 126 MiB)
[    1.773318] ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 129024 bytes
[    1.780158] ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 512
[    1.786860] ubi0: VID header offset: 512 (aligned 512), data offset: 2048
[    1.793648] ubi0: good PEBs: 1011, bad PEBs: 1, corrupted PEBs: 0
[    1.799741] ubi0: user volume: 4, internal volumes: 1, max. volumes count: 128
[    1.806969] ubi0: max/mean erase counter: 1360/1100, WL threshold: 4096, image sequence number: 228104625
[    1.816543] ubi0: available PEBs: 0, total reserved PEBs: 1011, PEBs reserved for bad PEB handling: 19
[    1.825913] ubi0: background thread "ubi_bgt0d" started, PID 318
[    1.833815] block ubiblock0_1: created from ubi0:1(rootfs)
[    1.837907] ubiblock: device ubiblock0_1 (rootfs) set to be root filesystem
[    1.851816] VFS: Mounted root (squashfs filesystem) readonly on device 254:0.
[    1.861257] Freeing unused kernel memory: 1224K
[    2.756451] init: Console is alive
[    2.758739] init: - watchdog -
[    3.289626] eth0: port 1 got link
[    4.020017] kmodloader: loading kernel modules from /etc/modules-boot.d/*
[    4.122460] dwc2 1e101000.ifxhcd: requested GPIO 495
[    4.288820] eth0: port 2 got link
[    4.980855] dwc2 1e101000.ifxhcd: DWC OTG Controller
[    4.984453] dwc2 1e101000.ifxhcd: new USB bus registered, assigned bus number 1
[    4.991763] dwc2 1e101000.ifxhcd: irq 62, io mem 0x00000000
[    4.997292] dwc2 1e101000.ifxhcd: Hardware does not support descriptor DMA mode -
[    5.004735] dwc2 1e101000.ifxhcd: falling back to buffer DMA mode.
[    5.012210] hub 1-0:1.0: USB hub found
[    5.015140] hub 1-0:1.0: 1 port detected
[    5.019926] kmodloader: done loading kernel modules from /etc/modules-boot.d/*
[    5.036289] init: - preinit -
[    5.701206] random: procd: uninitialized urandom read (4 bytes read, 23 bits of entropy available)
[    8.937196] UBIFS (ubi0:2): background thread "ubifs_bgt0_2" started, PID 391
[    8.965454] UBIFS (ubi0:2): recovery needed
[    9.086143] UBIFS (ubi0:2): recovery completed
[    9.089295] UBIFS (ubi0:2): UBIFS: mounted UBI device 0, volume 2, name "rootfs_data"
[    9.097020] UBIFS (ubi0:2): LEB size: 129024 bytes (126 KiB), min./max. I/O unit sizes: 2048 bytes/2048 bytes
[    9.106932] UBIFS (ubi0:2): FS size: 120637440 bytes (115 MiB, 935 LEBs), journal size 6064128 bytes (5 MiB, 47 LEBs)
[    9.117532] UBIFS (ubi0:2): reserved for root: 4952683 bytes (4836 KiB)
[    9.124155] UBIFS (ubi0:2): media format: w4/r0 (latest is w4/r0), UUID 83F0570F-17DF-47F1-BDFE-0286A4DC1AF7, small LPT model
[    9.139364] mount_root: switching to ubifs overlay
[    9.150435] urandom-seed: Seeding with /etc/urandom.seed
[    9.350810] procd: - early -
[    9.352405] procd: - watchdog -
[   10.000261] procd: - watchdog -
[   10.002455] procd: - ubus -
[   10.081440] random: ubusd: uninitialized urandom read (4 bytes read, 42 bits of entropy available)
[   10.090589] random: ubusd: uninitialized urandom read (4 bytes read, 42 bits of entropy available)
[   10.098686] random: ubusd: uninitialized urandom read (4 bytes read, 42 bits of entropy available)
[   10.107215] random: ubusd: uninitialized urandom read (4 bytes read, 42 bits of entropy available)
[   10.116639] random: ubusd: uninitialized urandom read (4 bytes read, 42 bits of entropy available)
[   10.125098] random: ubusd: uninitialized urandom read (4 bytes read, 42 bits of entropy available)
[   10.134305] random: ubusd: uninitialized urandom read (4 bytes read, 42 bits of entropy available)
[   10.143281] random: ubusd: uninitialized urandom read (4 bytes read, 42 bits of entropy available)
[   10.152491] procd: - init -
[   10.336619] eth0: port 2 lost link
[   10.338656] eth0: port 1 lost link
[   10.629691] kmodloader: loading kernel modules from /etc/modules.d/*
[   10.638308] IFXOS, Version 1.5.19 (c) Copyright 2009, Lantiq Deutschland GmbH
[   10.647892] NET: Registered protocol family 8
[   10.650861] NET: Registered protocol family 20
[   10.661512] PPP generic driver version 2.4.2
[   10.671603] ip6_tables: (C) 2000-2006 Netfilter Core Team
[   10.695447] Lantiq (VRX) DSL CPE MEI driver, version 1.5.17.6, (c) 2007-2015 Lantiq Beteiligungs-GmbH & Co. KG
[   10.695447] 
[   10.695447] Lantiq CPE API Driver version: DSL CPE API V4.17.18.6
[   10.717080] 
[   10.717080] Predefined debug level: 3
[   10.726456] Loading modules backported from Linux version wt-2017-01-31-0-ge882dff19e7f
[   10.733080] Backport generated by backports.git backports-20160324-13-g24da7d3c
[   10.802452] PCI: Enabling device 0000:01:00.0 (0000 -> 0002)
[   10.806798] PCI: Enabling device 0000:02:00.0 (0000 -> 0002)
[   10.812605] ath10k_pci 0000:02:00.0: pci irq legacy oper_irq_mode 1 irq_mode 0 reset_mode 0
[   11.010879] ath10k_pci 0000:02:00.0: Direct firmware load for ath10k/pre-cal-pci-0000:02:00.0.bin failed with error -2
[   11.020204] ath10k_pci 0000:02:00.0: Falling back to user helper
[   11.139789] firmware ath10k!pre-cal-pci-0000:02:00.0.bin: firmware_loading_store: map pages failed
[   11.475243] ath10k_pci 0000:02:00.0: qca988x hw2.0 target 0x4100016c chip_id 0x043202ff sub 0000:0000
[   11.483116] ath10k_pci 0000:02:00.0: kconfig debug 0 debugfs 1 tracing 0 dfs 1 testmode 1
[   11.498478] ath10k_pci 0000:02:00.0: firmware ver 10.2.4-1.0-00016 api 5 features no-p2p,raw-mode,mfp crc32 0c5668f8
[   11.507751] ath10k_pci 0000:02:00.0: Direct firmware load for ath10k/QCA988X/hw2.0/board-2.bin failed with error -2
[   11.518062] ath10k_pci 0000:02:00.0: Falling back to user helper
[   11.636807] firmware ath10k!QCA988X!hw2.0!board-2.bin: firmware_loading_store: map pages failed
[   11.644735] ath10k_pci 0000:02:00.0: board_file api 1 bmi_id N/A crc32 bebc7c08
[   12.777731] ath10k_pci 0000:02:00.0: htt-ver 2.1 wmi-op 5 htt-op 2 cal file max-sta 128 raw 0 hwcrypto 1
[   12.880485] ath: EEPROM regdomain: 0x833a
[   12.880509] ath: EEPROM indicates we should expect a country code
[   12.880530] ath: doing EEPROM country->regdmn map search
[   12.880545] ath: country maps to regdmn code: 0x37
[   12.880558] ath: Country alpha2 being used: GB
[   12.880568] ath: Regpair used: 0x37
[   12.938490] ip_tables: (C) 2000-2006 Netfilter Core Team
[   12.952200] Infineon Technologies DEU driver version 2.0.0 
[   13.050063] IFX DEU DES initialized (multiblock).
[   13.054325] IFX DEU AES initialized (multiblock).
[   13.058467] IFX DEU ARC4 initialized (multiblock).
[   13.063100] IFX DEU SHA1 initialized.
[   13.066725] IFX DEU MD5 initialized.
[   13.070307] IFX DEU SHA1_HMAC initialized.
[   13.074385] IFX DEU MD5_HMAC initialized.
[   13.085605] nf_conntrack version 0.5.0 (1947 buckets, 7788 max)
[   13.108713] PCI: Enabling device 0000:00:0e.0 (0000 -> 0002)
[   13.114546] owl-loader 0000:00:0e.0: fixup device configuration
[   13.121080] pci 0000:00:0e.0: [168c:002d] type 00 class 0x028000
[   13.121146] pci 0000:00:0e.0: reg 0x10: [mem 0x18000000-0x1800ffff]
[   13.121244] pci 0000:00:0e.0: PME# supported from D0 D3hot
[   13.121600] pci 0000:00:0e.0: BAR 0: assigned [mem 0x18000000-0x1800ffff]
[   13.131305] NET: Registered protocol family 24
[   13.154424] xt_time: kernel timezone is -0000
[   13.257298] PCI: Enabling device 0000:00:0e.0 (0000 -> 0002)
[   13.267775] ath: phy1: Ignoring endianness difference in EEPROM magic bytes.
[   13.275167] ath: EEPROM regdomain: 0x833a
[   13.275187] ath: EEPROM indicates we should expect a country code
[   13.275208] ath: doing EEPROM country->regdmn map search
[   13.275222] ath: country maps to regdmn code: 0x37
[   13.275235] ath: Country alpha2 being used: GB
[   13.275246] ath: Regpair used: 0x37
[   13.291127] ieee80211 phy1: Selected rate control algorithm 'minstrel_ht'
[   13.295929] ieee80211 phy1: Atheros AR9287 Rev:2 mem=0xb8000000, irq=30
[   13.306829] kmodloader: done loading kernel modules from /etc/modules.d/*
[   14.543083] random: jshn: uninitialized urandom read (4 bytes read, 61 bits of entropy available)
[   22.834949] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[   22.852721] device eth0 entered promiscuous mode
[   22.862636] device eth0.1 entered promiscuous mode
[   22.874280] IPv6: ADDRCONF(NETDEV_UP): br-lan: link is not ready
[   23.548922] eth0: port 2 got link
[   23.550913] eth0: port 1 got link
[   23.560939] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[   23.585941] br-lan: port 1(eth0.1) entered forwarding state
[   23.590201] br-lan: port 1(eth0.1) entered forwarding state
[   23.640796] IPv6: ADDRCONF(NETDEV_CHANGE): br-lan: link becomes ready
[   24.529316] ath: EEPROM regdomain: 0x817c
[   24.529342] ath: EEPROM indicates we should expect a country code
[   24.529355] ath: doing EEPROM country->regdmn map search
[   24.529368] ath: country maps to regdmn code: 0x37
[   24.529382] ath: Country alpha2 being used: IT
[   24.529393] ath: Regpair used: 0x37
[   24.529408] ath: regdomain 0x817c dynamically updated by user
[   24.529523] ath: EEPROM regdomain: 0x817c
[   24.529537] ath: EEPROM indicates we should expect a country code
[   24.529549] ath: doing EEPROM country->regdmn map search
[   24.529561] ath: country maps to regdmn code: 0x37
[   24.529573] ath: Country alpha2 being used: IT
[   24.529584] ath: Regpair used: 0x37
[   24.529597] ath: regdomain 0x817c dynamically updated by user
[   25.592716] br-lan: port 1(eth0.1) entered forwarding state
[   27.143326] IPv6: ADDRCONF(NETDEV_UP): wlan1: link is not ready
[   27.301885] device wlan1 entered promiscuous mode
[   31.124753] random: nonblocking pool is initialized
[   36.935794] IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
[   36.940994] br-lan: port 2(wlan1) entered forwarding state
[   36.946307] br-lan: port 2(wlan1) entered forwarding state
[   38.948706] br-lan: port 2(wlan1) entered forwarding state
[  245.604927] eth0: port 1 lost link
[  367.622694] eth0: port 1 got link

system.log

Sun May  6 08:12:20 2018 daemon.notice netifd: Interface 'wan' is now down
Sun May  6 08:12:20 2018 daemon.notice netifd: Interface 'wan' is setting up now
Sun May  6 08:12:20 2018 daemon.info pppd[20782]: Plugin pppoatm.so loaded.
Sun May  6 08:12:20 2018 daemon.info pppd[20782]: PPPoATM plugin_init
Sun May  6 08:12:20 2018 daemon.info pppd[20782]: PPPoATM setdevname_pppoatm - SUCCESS:0.8.35
Sun May  6 08:12:20 2018 daemon.notice pppd[20782]: pppd 2.4.7 started by root, uid 0
Sun May  6 08:12:20 2018 daemon.err pppd[20782]: connect(0.8.35): No such device
Sun May  6 08:12:20 2018 daemon.info pppd[20782]: Exit.
Sun May  6 08:12:47 2018 daemon.notice netifd: Interface 'wan' is now down
Sun May  6 08:12:47 2018 daemon.notice netifd: Interface 'wan' is setting up now
Sun May  6 08:12:47 2018 daemon.info pppd[22132]: Plugin pppoatm.so loaded.
Sun May  6 08:12:47 2018 daemon.info pppd[22132]: PPPoATM plugin_init
Sun May  6 08:12:47 2018 daemon.info pppd[22132]: PPPoATM setdevname_pppoatm - SUCCESS:0.8.35
Sun May  6 08:12:47 2018 daemon.notice pppd[22132]: pppd 2.4.7 started by root, uid 0
Sun May  6 08:12:47 2018 daemon.err pppd[22132]: connect(0.8.35): No such device
Sun May  6 08:12:48 2018 daemon.info pppd[22132]: Exit.
Sun May  6 08:12:48 2018 daemon.notice netifd: Interface 'wan' is now down
Sun May  6 08:12:48 2018 daemon.notice netifd: Interface 'wan' is setting up now

For two days I tried all possible settings with and without the alternative 'adsl.bin' firmware file, ATM bridge, Annex A G.992.5 or Annex A+L+M (all) and it did not work.
Today I just connected again the ADSL cable and it started to work like a charm. For the future, the setting is the same as explained above without the alternative 'adsl.bin' firmware file.