hostapd fails with nl80211 driver initialization on i.MX6 (RTL8812au)

I’m having some trouble with hostapd and nl80211. When I try to launch hostapd, this is what I get:

# /etc/init.d/hostapd start
Starting HOSTAP Daemon: Configuration file: /etc/hostapd.conf
nl80211: Driver does not support authentication/association or connect commands
nl80211 driver initialization failed.
hostapd_free_hapd_data: Interface wlan0 wasn't started

Is this due to the Wi-Fi driver (RTL8812au) or the nl80211 driver? I’m working on an ARM-based device with an i.MX6 processor. The driver is cross-compiled. Something strange: iwconfig works:

# iwconfig 
wlan0     unassociated  Nickname:""
          Mode:Auto  Frequency=2.412 GHz  Access Point: Not-Associated   
          Sensitivity:0/0  
          Retry:off   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality:0  Signal level:0  Noise level:0
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

But when I run iw list, nothing happens. Can someone help me with this problem? Additional info: - Yocto and custom BSP on the i.MX6 board - Kernel version: 3.14.28 - Linux distribution: Poky 1.8.1 - Wi-Fi USB key: Edimax EW-7811USC