USB WiFi works only after cold reboot

[Serge Voilokov]

Hi,

I have a problem on Raspberry PI-A with Realtek WiFi adapter.
After reboot on watchdog or kernel panic wifi doesn't init properly.
Sometimes wlan0 is not created, sometimes ethernet address is
ff:ff:ff:ff:ff:ff, firmware loading errors, etc.

After cold reboot it works file.

How can I avoid the cold reboot?
Now on boot I do several attempts of 'usbconfig reset' until wifi
starts working.
It doesn't seem reliable.
Is the other way to make cold reset of usb and/or wifi without rebooting the OS?

Thanks,
--serge