Suddenly my 5GHz Wifi disappeared

Suddenly this mornig I discovered, that 5Ghz network doesn’t work. I’ve restarted the router and nothing has changed and System Log contains following errors. Does anybody know how to diagnose further? Thanks for help…

2017-02-27T06:12:09+01:00 info kernel[]: [   18.577682] ath10k_pci 0000:02:00.0: pci irq msi oper_irq_mode 2 irq_mode 0 reset_mode 0
2017-02-27T06:12:09+01:00 warning kernel[]: [   18.753300] ath10k_pci 0000:02:00.0: Direct firmware load for ath10k/pre-cal-pci-0000:02:00.0.bin failed with error -2
2017-02-27T06:12:09+01:00 warning kernel[]: [   18.764043] ath10k_pci 0000:02:00.0: Falling back to user helper
2017-02-27T06:12:09+01:00 err kernel[]: [   18.773667] firmware ath10k!pre-cal-pci-0000:02:00.0.bin: firmware_loading_store: map pages failed
2017-02-27T06:12:09+01:00 warning kernel[]: [   18.782772] ath10k_pci 0000:02:00.0: Direct firmware load for ath10k/cal-pci-0000:02:00.0.bin failed with error -2
2017-02-27T06:12:09+01:00 warning kernel[]: [   18.793171] ath10k_pci 0000:02:00.0: Falling back to user helper
2017-02-27T06:12:09+01:00 err kernel[]: [   18.802636] firmware ath10k!cal-pci-0000:02:00.0.bin: firmware_loading_store: map pages failed
2017-02-27T06:12:09+01:00 info kernel[]: [   18.820053] ath10k_pci 0000:02:00.0: qca988x hw2.0 target 0x4100016c chip_id 0x043202ff sub 0000:0000
2017-02-27T06:12:09+01:00 info kernel[]: [   18.829332] ath10k_pci 0000:02:00.0: kconfig debug 0 debugfs 1 tracing 0 dfs 1 testmode 1
2017-02-27T06:12:09+01:00 info kernel[]: [   18.838953] ath10k_pci 0000:02:00.0: firmware ver 10.2.4.70.54 api 5 features no-p2p,raw-mode,mfp crc32 9d340dd9
2017-02-27T06:12:09+01:00 warning kernel[]: [   18.889266] ath10k_pci 0000:02:00.0: Direct firmware load for ath10k/QCA988X/hw2.0/board-2.bin failed with error -2
2017-02-27T06:12:09+01:00 warning kernel[]: [   18.899740] ath10k_pci 0000:02:00.0: Falling back to user helper
2017-02-27T06:12:09+01:00 err kernel[]: [   18.909284] firmware ath10k!QCA988X!hw2.0!board-2.bin: firmware_loading_store: map pages failed
2017-02-27T06:12:09+01:00 info kernel[]: [   18.918245] ath10k_pci 0000:02:00.0: board_file api 1 bmi_id N/A crc32 bebc7c08
2017-02-27T06:12:09+01:00 info kernel[]: [   20.061241] ath10k_pci 0000:02:00.0: htt-ver 2.1 wmi-op 5 htt-op 2 cal otp max-sta 128 raw 0 hwcrypto 1
2017-02-27T06:12:09+01:00 debug kernel[]: [   20.151824] ath: EEPROM regdomain: 0x0
2017-02-27T06:12:09+01:00 debug kernel[]: [   20.151830] ath: EEPROM indicates default country code should be used
2017-02-27T06:12:09+01:00 debug kernel[]: [   20.151832] ath: doing EEPROM country->regdmn map search
2017-02-27T06:12:09+01:00 debug kernel[]: [   20.151836] ath: country maps to regdmn code: 0x3a
2017-02-27T06:12:09+01:00 debug kernel[]: [   20.151839] ath: Country alpha2 being used: US
2017-02-27T06:12:09+01:00 debug kernel[]: [   20.151841] ath: Regpair used: 0x3a