Wifi doesn't start anymore

Hello, after the update from OpenWRT version 18.06.6 to version 19.07 my wifi doesn't start anymore.
I use the following WiFi cards:

root@rome01:~# lspci 
. . .
04:00.0 Network controller: Qualcomm Atheros AR928X Wireless Network Adapter (PCI-Express) (rev 01)
06:00.0 Network controller: Qualcomm Atheros QCA986x/988x 802.11ac Wireless Network Adapter

What have I tried?
I deleted the / etc / config / wireless folder and had it created:

root@rome01:~# rm /etc/config/wireless 
root@rome01:~# wifi config
root@rome01:~# cat /etc/config/wireless 

config wifi-device 'radio0'
	option type 'mac80211'
	option channel '36'
	option hwmode '11a'
	option path 'virtual/mac80211_hwsim/hwsim0'
	option htmode 'VHT80'
	option disabled '1'

config wifi-iface 'default_radio0'
	option device 'radio0'
	option network 'lan'
	option mode 'ap'
	option ssid 'OpenWrt'
	option encryption 'none'

config wifi-device 'radio1'
	option type 'mac80211'
	option channel '36'
	option hwmode '11a'
	option path 'virtual/mac80211_hwsim/hwsim1'
	option htmode 'VHT80'
	option disabled '1'

config wifi-iface 'default_radio1'
	option device 'radio1'
	option network 'lan'
	option mode 'ap'
	option ssid 'OpenWrt'
	option encryption 'none'

config wifi-device 'radio2'
	option type 'mac80211'
	option channel '36'
	option hwmode '11a'
	option path 'pci0000:00/0000:00:15.0/0000:06:00.0'
	option htmode 'VHT80'
	option disabled '1'

config wifi-iface 'default_radio2'
	option device 'radio2'
	option network 'lan'
	option mode 'ap'
	option ssid 'OpenWrt'
	option encryption 'none'

config wifi-device 'radio3'
	option type 'mac80211'
	option channel '36'
	option hwmode '11a'
	option path 'pci0000:00/0000:00:07.0/0000:04:00.0'
	option htmode 'HT20'
	option disabled '1'

config wifi-iface 'default_radio3'
	option device 'radio3'
	option network 'lan'
	option mode 'ap'
	option ssid 'OpenWrt'
	option encryption 'none'

If I now want to activate a wireless network, I see the following error message in the system log

Thu Jan 16 16:16:06 2020 daemon.notice netifd: radio2 (6100): ./mac80211.sh: eval: line 792: /usr/sbin/hostapd: not found
Thu Jan 16 16:16:06 2020 daemon.notice netifd: radio2 (6100): cat: can't open '/var/run/wifi-phy2.pid': No such file or directory
Thu Jan 16 16:16:06 2020 daemon.notice netifd: radio2 (6100): WARNING (wireless_add_process): executable path /usr/sbin/hostapd does not match process  path (/proc/exe)
Thu Jan 16 16:16:06 2020 daemon.notice netifd: radio2 (6100): Command failed: Invalid argument
Thu Jan 16 16:16:06 2020 daemon.notice netifd: radio2 (6100): Device setup failed: HOSTAPD_START_FAILED
Thu Jan 16 16:16:22 2020 daemon.notice netifd: radio2 (6378): ./mac80211.sh: eval: line 792: /usr/sbin/hostapd: not found
Thu Jan 16 16:16:22 2020 daemon.notice netifd: radio2 (6378): cat: can't open '/var/run/wifi-phy2.pid': No such file or directory
Thu Jan 16 16:16:22 2020 daemon.notice netifd: radio2 (6378): WARNING (wireless_add_process): executable path /usr/sbin/hostapd does not match process  path (/proc/exe)
Thu Jan 16 16:16:22 2020 daemon.notice netifd: radio2 (6378): Command failed: Invalid argument
Thu Jan 16 16:16:22 2020 daemon.notice netifd: radio2 (6378): Device setup failed: HOSTAPD_START_FAILED

My kernel log also shows me several errors. However, when loading the firmware. This topic has been discussed here very often and for a long time. However, I almost never found a solution. I also had these messages with the OpenWRT version 18.06.6.

[   10.484992] ath10k_pci 0000:06:00.0: pci irq msi oper_irq_mode 2 irq_mode 0 reset_mode 0
[   10.726085] ath10k_pci 0000:06:00.0: Direct firmware load for ath10k/pre-cal-pci-0000:06:00.0.bin failed with error -2
[   10.736937] ath10k_pci 0000:06:00.0: Falling back to user helper
[   11.747476] firmware ath10k!pre-cal-pci-0000:06:00.0.bin: firmware_loading_store: map pages failed
[   11.756992] ath10k_pci 0000:06:00.0: Direct firmware load for ath10k/cal-pci-0000:06:00.0.bin failed with error -2
[   11.767501] ath10k_pci 0000:06:00.0: Falling back to user helper
[   11.780174] firmware ath10k!cal-pci-0000:06:00.0.bin: firmware_loading_store: map pages failed
[   11.791983] ath10k_pci 0000:06:00.0: Direct firmware load for ath10k/QCA988X/hw2.0/firmware-6.bin failed with error -2
[   11.802839] ath10k_pci 0000:06:00.0: Falling back to user helper
[   11.816873] firmware ath10k!QCA988X!hw2.0!firmware-6.bin: firmware_loading_store: map pages failed
[   11.831251] ath10k_pci 0000:06:00.0: qca988x hw2.0 target 0x4100016c chip_id 0x043222ff sub 0000:0000
[   11.840623] ath10k_pci 0000:06:00.0: kconfig debug 0 debugfs 1 tracing 0 dfs 1 testmode 1
[   11.850782] ath10k_pci 0000:06:00.0: firmware ver 10.2.4-1.0-00047 api 5 features no-p2p,raw-mode,mfp,allows-mesh-bcast crc32 35bd9258
[   11.895867] ath10k_pci 0000:06:00.0: Direct firmware load for ath10k/QCA988X/hw2.0/board-2.bin failed with error -2
[   11.906378] ath10k_pci 0000:06:00.0: Falling back to user helper
[   11.919652] firmware ath10k!QCA988X!hw2.0!board-2.bin: firmware_loading_store: map pages failed
[   11.929498] ath10k_pci 0000:06:00.0: board_file api 1 bmi_id N/A crc32 bebc7c08
[   13.072911] ath10k_pci 0000:06:00.0: htt-ver 2.1 wmi-op 5 htt-op 2 cal otp max-sta 128 raw 0 hwcrypto 1
[   13.192719] ath: EEPROM regdomain: 0x0
[   13.192727] ath: EEPROM indicates default country code should be used
[   13.192730] ath: doing EEPROM country->regdmn map search
[   13.192735] ath: country maps to regdmn code: 0x3a
[   13.192739] ath: Country alpha2 being used: US
[   13.192741] ath: Regpair used: 0x3a
[   13.639077] ath: phy3: ASPM enabled: 0x2
[   13.643079] ath: EEPROM regdomain: 0x0
[   13.643081] ath: EEPROM indicates default country code should be used
[   13.643083] ath: doing EEPROM country->regdmn map search
[   13.643088] ath: country maps to regdmn code: 0x3a
[   13.643091] ath: Country alpha2 being used: US
[   13.643093] ath: Regpair used: 0x3a
[   13.660862] ieee80211 phy3: Selected rate control algorithm 'minstrel_ht'
[   13.662078] ieee80211 phy3: Atheros AR9280 Rev:2 mem=0xffffc90000150000, irq=19

Under make menuconfig I tried almost all wireless network settings

 < > wpa-supplicant-basic................... WPA Supplicant (with 11r and 11w)
< > wpa-supplicant-mesh-openssl........ WPA Supplicant (with 802.11s and SAE)
< >   wpa-supplicant-mesh-wolfssl........ WPA Supplicant (with 802.11s and SAE)
< > wpa-supplicant-mini..................... WPA Supplicant (minimal version)
< >   wpa-supplicant-openssl.................................... WPA Supplicant
< >   wpa-supplicant-p2p............... WPA Supplicant (with Wi-Fi P2P support)
< >   wpa-supplicant-wolfssl.................................... WPA Supplicant
<*> wpad......................... IEEE 802.1x Authenticator/Supplicant (full)
< >   wpad-basic... IEEE 802.1x Authenticator/Supplicant (WPA-PSK, 11r and 11w)
< >   wpad-mesh-openssl
< >     wpad-mesh-wolfssl
< >   wpad-mini............ IEEE 802.1x Authenticator/Supplicant (WPA-PSK only)
< >     wpad-openssl................. IEEE 802.1x Authenticator/Supplicant (full)
< >       wpad-wolfssl................. IEEE 802.1x Authenticator/Supplicant (full)       

over and over again the absolutely same result!
The file / usr / sbin / hostpad does not exist
Can't it be that I have to build the whole build again from scratch?
Do you have any idea what else I can do?
Greetings from Stefan Harbich

What's your router model? Do you by chance have a device that was using ar71xx, and just got the ath79 upgrade which you installed while saving the settings?

Check this

root@rome01:~# dmidecode -t 2
# dmidecode 3.2
Getting SMBIOS data from sysfs.
SMBIOS 2.7 present.

Handle 0x0002, DMI type 2, 8 bytes
Base Board Information
	Manufacturer: PC Engines
	Product Name: APU
	Version: 1.0
	Serial Number: 953809

The radios were detected as radio2 and radio3. Radio 0 and 1 are simulated radios, not sure why those were created but you should just delete them and re-number 2 and 3.

Is wpad installed?

./mac80211.sh: eval: line 792: /usr/sbin/hostapd: not found

This means that the executable file referenced doesn't exist (this would be part of a wpad package, is any installed?) or one of the libraries it needs to load doesn't exist.

x86 builds don't include any wifi related packages, they have to be installed.

What would be the best way to rebuild the building with the existing .config completely. I think I've tried too much.

I am totally desperate for the next build. Now I get the following message

[    8.922064] mount_root: loading kmods from internal overlay
[    8.933697] kmodloader: failed to open /tmp/overlay/upper/lib/modules/4.14.162/ath10k_core.ko
[    8.943095] kmodloader: failed to open /tmp/overlay/upper/lib/modules/4.14.162/ath10k_pci.ko
[    8.952700] kmodloader: failed to open /tmp/overlay/upper/lib/modules/4.14.162/ath9k.ko
[    8.961637] kmodloader: failed to open /tmp/overlay/upper/lib/modules/4.14.162/ath9k_common.ko
[    8.971478] kmodloader: failed to open /tmp/overlay/upper/lib/modules/4.14.162/ath9k_hw.ko
[    8.981129] kmodloader: failed to open /tmp/overlay/upper/lib/modules/4.14.162/mac80211_hwsim.ko

I just do not know how to go on!

I'm starting to give up.

Why not try the image builder as a compromise?

I don't know what you're trying to achieve and what degree of customisation you need, but adding/removing packages, custom files and UCI scripts etc. can perfectly be done with the image builder.

While you get your APU2 up and running again you can start your own build with a clean slate (hint: ./scripts/diffconfig.sh is a tremendous help to see where your config actually differs from vanilla), maybe test your builds in a VM before pushing them again.

failed to open /tmp/overlay/upper/lib/modules/4.14.162/ath10k_core.ko

This means that your overlay partition failed to mount and it fell back to a RAM disk (/tmp). Of course without the overlay, packages and files that you added at run time (i.e. not squashed into the rootfs at compile time) are not accessible. Possibly the flash is full or there is a drive hardware failure, either way check earlier in the log for why it did not mount.

I'm along with @Borromini wondering what you're needing to do that can't be done with a release build.