WIFI USB adapter not detected RPi 3b after reboot

Question

I'm using builtin WIFI adapter 802.11n Wireless LAN.

ifup wlan0 shows:

wpa_supplicant: /sbin/wpa_supplicant daemon failed to start
run-parts: /etc/network/if-pre-up.d/wpasupplicant exited with return code 1
Failed to bring up wlan0.

I tried to update, upgrade, rpi-update, it hasn't helped, but now rpi is updated to the latest firmware.

Linux raspberrypi 4.9.13-v7+ #972 SMP Sun Feb 26 20:27:50 GMT 2017 armv7l GNU/Linux

lsusb shows:

Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

lsmod shows:

Module                  Size  Used by
bnep                   12051  2 
hci_uart               19956  1 
btbcm                   7916  1 hci_uart
bluetooth             365511  22 hci_uart,bnep,btbcm
brcmfmac              222720  0 
brcmutil                9092  1 brcmfmac
cfg80211              542899  1 brcmfmac
rfkill                 20851  3 bluetooth,cfg80211
snd_bcm2835            24427  0 
snd_pcm                97226  1 snd_bcm2835
snd_timer              23840  1 snd_pcm
snd                    70032  3 snd_timer,snd_bcm2835,snd_pcm
bcm2835_gpiomem         3940  0 
w1_gpio                 4818  0 
wire                   32581  1 w1_gpio
cn                      5889  1 wire
uio_pdrv_genirq         3923  0 
uio                    10204  1 uio_pdrv_genirq
fixed                   3285  0 
ipv6                  406215  22 

Answer 1

Mine wouldn't work until I plugged in an external wifi dongle.

I had my wifi info in /etc/wpa_supplicant/wpa_supplicant.conf prior to plugging in the dongle, and tried rebooting.

~ $ sudo vi /etc/wpa_supplicant/wpa_supplicant.conf

network={
  ssid="NETWORK_NAME"
  psk="PASSWORD"
  key_mgmt=WPA-PSK
}

After the wifi connection was established, I could remove the dongle and my on-board would continue to work. (maybe it's a safety feature?)