I can confirm that your commit (https://github.com/openwrt/openwrt/commit/0d9939a0d0cdc6164eb9a460af8d3c6fa0d2e3ef) is working on my C6U but on another board I'm getting:
[ 10.546355] mt7603e 0000:01:00.0: Firmware Version: ap_pcie
[ 10.551980] mt7603e 0000:01:00.0: Build Time: 20160107100755
[ 10.585058] mt7603e 0000:01:00.0: firmware init done
[ 10.762519] ------------[ cut here ]------------
[ 10.767229] WARNING: CPU: 1 PID: 742 at backports-5.10.16-1/net/wireless/core.c:875 wiphy_register+0xd8c/0xd94 [cfg80211]
[ 10.778151] Modules linked in: mt7603e(+) mt76_connac_lib mt76 mac80211 ipt_REJECT cfg80211 xt_time xt_tcpudp xt_multiport xt_mark xt_mac xt_limit xt_comment xt_TCPMSS xt_LOG slhc nf_reject_ipv4 nf_log_ipv4 nf_defrag_ipv6 nf_defrag_ipv4 iptable_mangle iptable_filter ip_tables crc_ccitt compat ledtrig_usbport nf_log_ipv6 nf_log_common ip6table_mangle ip6table_filter ip6_tables ip6t_REJECT x_tables nf_reject_ipv6 leds_gpio xhci_plat_hcd xhci_pci xhci_mtk xhci_hcd gpio_button_hotplug usbcore nls_base usb_common
[ 10.823074] CPU: 1 PID: 742 Comm: kmodloader Not tainted 5.4.102 #0
[ 10.829309] Stack : 00000005 8007d86c 806b0000 806b3b74 80720000 806b3b3c 806b2c90 86d5796c
[ 10.837632] 80850000 87f5c188 806fcd03 80647dd4 00000001 00000001 86d57910 44c617d6
[ 10.845953] 00000000 00000000 80890000 00000000 00000030 00000106 20646574 2e342e35
[ 10.854274] 00000000 00000000 00000000 000c8f22 80000000 80720000 00000000 86f01248
[ 10.862596] 00000009 86875cdc 00000001 00000005 00000002 8034fcc4 00000004 80850004
[ 10.870917] ...
[ 10.873354] Call Trace:
[ 10.875810] [<8000b70c>] show_stack+0x30/0x100
[ 10.880262] [<8058c1e0>] dump_stack+0xa4/0xdc
[ 10.884615] [<8002c008>] __warn+0xc0/0x10c
[ 10.888696] [<8002c0b0>] warn_slowpath_fmt+0x5c/0xac
[ 10.893670] [<86f01248>] wiphy_register+0xd8c/0xd94 [cfg80211]
[ 10.899612] [<868014a8>] ieee80211_register_hw+0x9b8/0xd88 [mac80211]
[ 10.906069] [<86e6380c>] mt76_register_device+0x208/0x340 [mt76]
[ 10.912086] [<86e3280c>] mt7603_register_device+0x9a0/0xb74 [mt7603e]
[ 10.918518] [<86e3016c>] init_module+0x4a16c/0x4b364 [mt7603e]
[ 10.924459] ---[ end trace e5c48b31d7c5c199 ]---
[ 10.930674] mt7603e: probe of 0000:01:00.0 failed with error -22
[ 10.942665] mt7621-pci 1e140000.pcie: bus=2 slot=1 irq=24
[ 10.948112] pci 0000:00:01.0: enabling device (0004 -> 0007)
[ 10.953777] mt7615e 0000:02:00.0: enabling device (0000 -> 0002)
and then after a minute:
[ 70.933038] rcu: INFO: rcu_sched self-detected stall on CPU
[ 70.938616] rcu: 1-....: (14997 ticks this GP) idle=262/1/0x40000002 softirq=510/510 fqs=7500
[ 70.947272] (t=15003 jiffies g=-239 q=175)
[ 70.951436] NMI backtrace for cpu 1
[ 70.954914] CPU: 1 PID: 742 Comm: kmodloader Tainted: G W 5.4.102 #0
[ 70.962531] Stack : 80700000 8007d86c 806b0000 806b3b74 80720000 806b3b3c 806b2c90 87c0fd3c
[ 70.970857] 80850000 87f5c188 806fcd03 80647dd4 00000001 00000001 87c0fce0 44c617d6
[ 70.979179] 00000000 00000000 80890000 00000000 00000030 00000120 20202020 2e342e35
[ 70.987500] 00000000 00000003 00000000 000e9222 80000000 80720000 00000000 00000001
[ 70.995822] 8063be30 806fa2d0 80700000 00000000 00000002 8034fcc4 00000004 80850004
[ 71.004143] ...
[ 71.006579] Call Trace:
[ 71.009045] [<8000b70c>] show_stack+0x30/0x100
[ 71.013499] [<8058c1e0>] dump_stack+0xa4/0xdc
[ 71.017847] [<8059283c>] nmi_cpu_backtrace+0xe4/0x134
[ 71.022879] [<805929e8>] nmi_trigger_cpumask_backtrace+0x15c/0x194
[ 71.029060] [<8008d5f4>] rcu_dump_cpu_stacks+0xe0/0x12c
[ 71.034270] [<80092274>] rcu_sched_clock_irq+0x6e0/0x948
[ 71.039573] [<80097378>] update_process_times+0x2c/0x78
[ 71.044794] [<800a96d8>] tick_handle_periodic+0x34/0xd0
[ 71.050023] [<803e4ee0>] gic_compare_interrupt+0x7c/0x9c
[ 71.055314] [<80084b88>] handle_percpu_devid_irq+0xbc/0x19c
[ 71.060878] [<8007eaa4>] generic_handle_irq+0x40/0x58
[ 71.065915] [<802f0920>] gic_handle_local_int+0x98/0x120
[ 71.071205] [<802f0b6c>] gic_irq_dispatch+0x10/0x20
[ 71.076064] [<8007eaa4>] generic_handle_irq+0x40/0x58
[ 71.081114] [<805acd1c>] do_IRQ+0x1c/0x2c
[ 71.085109] [<802f03c8>] plat_irq_dispatch+0x64/0x104
[ 71.090142] [<80006dc8>] except_vec_vi_end+0xb8/0xc4
[ 71.095086] [<805aac44>] down_write+0x34/0x5c
[ 71.099429] [<803e3778>] led_trigger_register+0x144/0x214
[ 71.104933] [<8685740c>] ieee80211_led_init+0x3c/0x180 [mac80211]
[ 71.111051] [<86801160>] ieee80211_register_hw+0x670/0xd88 [mac80211]
[ 71.117507] [<86e6380c>] mt76_register_device+0x208/0x340 [mt76]
[ 71.123505] [<868f44e8>] mt7615_register_device+0x148/0x1a8 [mt7615e]
[ 71.129926] [<868f5bd8>] mt7615_mmio_probe+0x200/0x218 [mt7615e]
[ 71.135916] [<80314a14>] pci_device_probe+0xbc/0x150
[ 71.140863] [<8036087c>] really_probe+0x104/0x358
[ 71.145550] [<80360fb4>] device_driver_attach+0x74/0x7c
[ 71.150755] [<8036101c>] __driver_attach+0x60/0x100
[ 71.155632] [<8035e864>] bus_for_each_dev+0x68/0xa4
[ 71.160495] [<8035fbd8>] bus_add_driver+0x1f4/0x204
[ 71.165355] [<803616b0>] driver_register+0x84/0x148
[ 71.170214] [<8000161c>] do_one_initcall+0x7c/0x1dc
[ 71.175083] [<800b4598>] do_init_module+0x60/0x228
[ 71.179856] [<800b6778>] load_module+0x1f9c/0x2530
[ 71.184629] [<800b6e78>] sys_init_module+0x16c/0x1a8
[ 71.189583] [<80014578>] syscall_common+0x34/0x58
Does this output mean that is something wrong with my calibration data?
the other board is what? another C6U? same version?
I got custom board with exact same hardware as C6U but with swapped pcie lines for MT7603 and MT7613, so I just swapped them in dts file:
&pcie0 {
mt76@0,0 {
compatible = "mediatek,mt76";
reg = <0x0000 0 0 0 0>;
mediatek,mtd-eeprom = <&radio 0x8000>;
mtd-mac-address = <&config 0x8>;
ieee80211-freq-limit = <5000000 6000000>;
};
};
&pcie1 {
mt76@0,0 {
compatible = "mediatek,mt76";
reg = <0x0000 0 0 0 0>;
mediatek,mtd-eeprom = <&radio 0x0>;
mtd-mac-address = <&config 0x8>;
mtd-mac-address-increment = <(-1)>;
ieee80211-freq-limit = <2400000 2500000>;
};
};
Actually I was a bit wrong in last posts, if I set dts with mtd-mac-address-increment = <(-1)>; for MT7603 I get into kernel panic:
[ 12.782386] mt7621-pci 1e140000.pcie: bus=1 slot=0 irq=23
[ 12.787857] pci 0000:00:00.0: enabling device (0004 -> 0007)
[ 12.793524] mt7603e 0000:01:00.0: enabling device (0000 -> 0002)
[ 12.799722] mt7603e 0000:01:00.0: ASIC revision: 76030010
[ 12.900201] random: crng init done
[ 12.903628] random: 7 urandom warning(s) missed due to ratelimiting
[ 13.422564] mt7603e 0000:01:00.0: Firmware Version: ap_pcie
[ 13.428220] mt7603e 0000:01:00.0: Build Time: 20160107100755
[ 13.457624] mt7603e 0000:01:00.0: firmware init done
[ 13.638825] ------------[ cut here ]------------
[ 13.643572] WARNING: CPU: 0 PID: 730 at backports-5.10.16-1/net/wireless/core.c:875 wiphy_register+0xd8c/0xd94 [cfg80211]
[ 13.654502] Modules linked in: mt7603e(+) mt76_connac_lib mt76 mac80211 ipt_REJECT cfg80211 xt_time xt_tcpudp xt_multiport xt_mark xt_mac xt_limit xt_comment xt_TCPMSS xt_LOG slhc nf_reject_ipv4 nf_log_ipv4 nf_defrag_ipv6 nf_defrag_ipv4 iptable_mangle iptable_filter ip_tables crc_ccitt compat ledtrig_usbport nf_log_ipv6 nf_log_common ip6table_mangle ip6table_filter ip6_tables ip6t_REJECT x_tables nf_reject_ipv6 leds_gpio xhci_plat_hcd xhci_pci xhci_mtk xhci_hcd gpio_button_hotplug usbcore nls_base usb_common
[ 13.699441] CPU: 0 PID: 730 Comm: kmodloader Not tainted 5.4.102 #0
[ 13.705677] Stack : 00000005 8007d86c 806b0000 806b3c48 80720000 806b3c10 806b2d64 868f396c
[ 13.714001] 80c40000 87479488 806fcd03 80647e64 00000000 00000001 868f3910 a27c8c3d
[ 13.722319] 00000000 00000000 80c80000 00000000 00000030 000000fe 20646574 2e342e35
[ 13.730637] 00000000 00000000 00000000 000aac31 80000000 80720000 00000000 87601248
[ 13.738955] 00000009 87275cdc 00000001 00000005 00000002 8034fcc4 00000000 80c40000
[ 13.747274] ...
[ 13.749707] Call Trace:
[ 13.752161] [<8000b70c>] show_stack+0x30/0x100
[ 13.756610] [<8058c1e0>] dump_stack+0xa4/0xdc
[ 13.760959] [<8002c008>] __warn+0xc0/0x10c
[ 13.765037] [<8002c0b0>] warn_slowpath_fmt+0x5c/0xac
[ 13.770006] [<87601248>] wiphy_register+0xd8c/0xd94 [cfg80211]
[ 13.775944] [<872014a8>] ieee80211_register_hw+0x9b8/0xd88 [mac80211]
[ 13.782394] [<8719380c>] mt76_register_device+0x208/0x340 [mt76]
[ 13.788407] [<86c1280c>] mt7603_register_device+0x9a0/0xb74 [mt7603e]
[ 13.794834] [<86c1016c>] 0x86c1016c
[ 13.798475] ---[ end trace 7f2fa1eee56348ad ]---
[ 13.804613] mt7603e: probe of 0000:01:00.0 failed with error -22
[ 13.816691] mt7621-pci 1e140000.pcie: bus=2 slot=1 irq=24
[ 13.822202] pci 0000:00:01.0: enabling device (0004 -> 0007)
[ 13.827883] mt7615e 0000:02:00.0: enabling device (0000 -> 0002)
[ 13.842115] CPU 0 Unable to handle kernel paging request at virtual address 07797000, epc == 80076cb0, ra == 80076c8c
[ 13.852697] Oops[#1]:
[ 13.854966] CPU: 0 PID: 730 Comm: kmodloader Tainted: G W 5.4.102 #0
[ 13.862581] $ 0 : 00000000 00000001 00000000 07797000
[ 13.867785] $ 4 : 871533f8 00000000 4f000000 86cd6380
[ 13.872986] $ 8 : 00000000 805a69bc 00000000 f4dfdfa6
[ 13.878187] $12 : 8ad87137 2219ec5e b723fa9c 435bbda8
[ 13.883388] $16 : 871533f0 00000000 00000001 871533f8
[ 13.888590] $20 : 00000002 00800000 871533fc 868f3a50
[ 13.893792] $24 : 00000000 e44a31b6
[ 13.898993] $28 : 868f2000 868f3a28 80700000 80076c8c
[ 13.904195] Hi : 001dc681
[ 13.907056] Lo : 24c118ce
[ 13.909932] epc : 80076cb0 rwsem_down_write_slowpath+0xa0/0x450
[ 13.915993] ra : 80076c8c rwsem_down_write_slowpath+0x7c/0x450
[ 13.922050] Status: 11008402 KERNEL EXL
[ 13.925955] Cause : 4080000c (ExcCode 03)
[ 13.929939] BadVA : 07797000
[ 13.932800] PrId : 0001992f (MIPS 1004Kc)
[ 13.936869] Modules linked in: mt7615e(+) mt7615_common mt7603e mt76_connac_lib mt76 mac80211 ipt_REJECT cfg80211 xt_time xt_tcpudp xt_multiport xt_mark xt_mac xt_limit xt_comment xt_TCPMSS xt_LOG slhc nf_reject_ipv4 nf_log_ipv4 nf_defrag_ipv6 nf_defrag_ipv4 iptable_mangle iptable_filter ip_tables crc_ccitt compat ledtrig_usbport nf_log_ipv6 nf_log_common ip6table_mangle ip6table_filter ip6_tables ip6t_REJECT x_tables nf_reject_ipv6 leds_gpio xhci_plat_hcd xhci_pci xhci_mtk xhci_hcd gpio_button_hotplug usbcore nls_base usb_common
[ 13.983645] Process kmodloader (pid: 730, threadinfo=64a180db, task=78cd35ab, tls=77e75ec8)
[ 13.991949] Stack : 45adbdc4 98e8b532 80c74f74 868f3a7c 871533f8 00000000 868f3a80 80357d20
[ 14.000269] 00000001 868f3a48 871533fc 07797000 874790e0 00000000 fffee87a 80358284
[ 14.008588] 87153374 87285ca8 871533f0 80712cc0 80710000 00800000 00000000 00000005
[ 14.016906] 00000005 803e3778 00000000 00000000 00000000 00000000 00000000 87284c20
[ 14.025224] 00000000 0000000e 00000000 00000001 00000000 8725740c 87284c20 00000000
[ 14.033542] ...
[ 14.035974] Call Trace:
[ 14.038408] [<80076cb0>] rwsem_down_write_slowpath+0xa0/0x450
[ 14.044152] [<803e3778>] led_trigger_register+0x144/0x214
[ 14.049656] [<8725740c>] ieee80211_led_init+0x3c/0x180 [mac80211]
[ 14.055769] [<87201160>] ieee80211_register_hw+0x670/0xd88 [mac80211]
[ 14.062218] [<8719380c>] mt76_register_device+0x208/0x340 [mt76]
[ 14.068211] [<876744e8>] mt7615_register_device+0x148/0x1a8 [mt7615e]
[ 14.074627] [<87675bd8>] mt7615_mmio_probe+0x200/0x218 [mt7615e]
[ 14.080611] [<80314a14>] pci_device_probe+0xbc/0x150
[ 14.085554] [<8036087c>] really_probe+0x104/0x358
[ 14.090238] [<80360fb4>] device_driver_attach+0x74/0x7c
[ 14.095439] [<8036101c>] __driver_attach+0x60/0x100
[ 14.100313] [<8035e864>] bus_for_each_dev+0x68/0xa4
[ 14.105172] [<8035fbd8>] bus_add_driver+0x1f4/0x204
[ 14.110028] [<803616b0>] driver_register+0x84/0x148
[ 14.114884] [<8000161c>] do_one_initcall+0x7c/0x1dc
[ 14.119749] [<800b4598>] do_init_module+0x60/0x228
[ 14.124518] [<800b6778>] load_module+0x1f9c/0x2530
[ 14.129287] [<800b6e78>] sys_init_module+0x16c/0x1a8
[ 14.134236] [<80014578>] syscall_common+0x34/0x58
[ 14.138918] Code: afb60028 afa3002c 2e310001 <ac770000> 12c200d5 00000000 8e020000 30430001 106000bb
[ 14.148627]
[ 14.150534] ---[ end trace 7f2fa1eee56348ae ]---
[ 14.155156] Kernel panic - not syncing: Fatal exception
But if I set mtd-mac-address-increment = <(-1)>; for MT7613 - at least I'm able to log in.
Looks like that MT7613 is working, but MT7603 is not. Any suggestions how to debug this situation? 
May be LED settings changed for wifi mt7603?, There is a kernel exception while setting LED.
Not sure what do you mean. Can I solve my problem just within dts file?
leds {
compatible = "gpio-leds";
led_power: power {
label = "green:power";
gpios = <&gpio 4 GPIO_ACTIVE_LOW>;
};
usb {
label = "green:usb";
gpios = <&gpio 13 GPIO_ACTIVE_LOW>;
trigger-sources = <&ehci_port2>;
linux,default-trigger = "usbport";
};
wan-orange {
label = "orange:wan";
gpios = <&gpio 14 GPIO_ACTIVE_LOW>;
};
lan {
label = "green:lan";
gpios = <&gpio 15 GPIO_ACTIVE_LOW>;
};
wifi5g {
label = "green:wifi5g";
gpios = <&gpio 16 GPIO_ACTIVE_LOW>;
linux,default-trigger = "phy1tpt";
};
wifi2g {
label = "green:wifi2g";
gpios = <&gpio 18 GPIO_ACTIVE_LOW>;
linux,default-trigger = "phy0tpt";
};
wan-green {
label = "green:wan";
gpios = <&gpio 45 GPIO_ACTIVE_LOW>;
};
};
I've thought that leds part won't affect so drastically for driver loading. There is wifi2g at GPIO 18 - but that is just output indicating that corresponding wi-fi is working. There is GPIO 16 for wifi5g, GPIO 16 state does not effect on loading MT7613/MT7615 driver. GPIO 18 state does not effect on loading MT7603 driver.
WARNING: CPU: 0 PID: 742 at backports-5.10.16-1/net/wireless/core.c:875 wiphy_register+0xd8c/0xd94 [cfg80211]
As of backports-5.10.16-1/net/wireless/core.c file at line 845 I have
874: if (!have_band) {
875: WARN_ON(1);
876: return -EINVAL;
877: }
Not sure what should I do, because this is just a warning.
I found something similar in old issues - https://github.com/abperiasamy/rtl8812AU_8821AU_linux/issues/22, but the issue was not solved yet.