Created attachment 919693 [details] dmesg_3.14.8 hostapd starts on kernel-3.14.8-200.fc20.x86_64, but fails on kernel-3.15.6-200.fc20.x86_64: hostapd[4865]: Configuration file: /etc/hostapd/hostapd.conf hostapd[4865]: nl80211: Failed to set interface wlan0 into AP mode hostapd[4865]: nl80211 driver initialization failed. I'll attach dmesg and lsmod files.
Created attachment 919694 [details] dmesg_3.15.6
Created attachment 919695 [details] lsmod_3.14.8
Created attachment 919696 [details] lsmod_3.15.6
lsusb: Bus 001 Device 005: ID 148f:5370 Ralink Technology, Corp. RT5370 Wireless Adapter
It works for me on 3.15.7-200.fc20.x86_64. Perhaps systemd change name of the wlan0 interface (see http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames ), what shows "iw dew" on your system ?
> what shows "iw dew" on your system ? I mean: "iw dev"
hostapd failed to start once on 3.14.8 kernel too, but disconnecting and reconnecting the device helped. The same worked on 3.15.8. hostapd -d output when it fails: random: Trying to read entropy from /dev/random Configuration file: /etc/hostapd/hostapd.conf ctrl_interface_group=10 (from group name 'wheel') nl80211: interface wlan0 in phy phy0 rfkill: initial event: idx=0 type=1 op=0 soft=0 hard=0 nl80211: Using driver-based off-channel TX nl80211: Add own interface ifindex 4 nl80211: Set mode ifindex 4 iftype 3 (AP) nl80211: Setup AP - device_ap_sme=0 use_monitor=0 nl80211: Subscribe to mgmt frames with AP handle 0x17fb2a0 nl80211: Register frame type=0xb0 nl_handle=0x17fb2a0 nl80211: Register frame match - hexdump(len=0): [NULL] nl80211: Register frame type=0x0 nl_handle=0x17fb2a0 nl80211: Register frame match - hexdump(len=0): [NULL] nl80211: Register frame type=0x20 nl_handle=0x17fb2a0 nl80211: Register frame match - hexdump(len=0): [NULL] nl80211: Register frame type=0xa0 nl_handle=0x17fb2a0 nl80211: Register frame match - hexdump(len=0): [NULL] nl80211: Register frame type=0xc0 nl_handle=0x17fb2a0 nl80211: Register frame match - hexdump(len=0): [NULL] nl80211: Register frame type=0xd0 nl_handle=0x17fb2a0 nl80211: Register frame match - hexdump(len=0): [NULL] nl80211: Register frame command failed (type=208): ret=-114 (Operation already in progress) nl80211: Register frame match - hexdump(len=0): [NULL] nl80211: Failed to set interface wlan0 into AP mode netlink: Operstate: linkmode=0, operstate=6 nl80211: Set mode ifindex 4 iftype 2 (STATION) nl80211 driver initialization failed. Anyway, I am closing this bug, as the workaround is to physically disconnect and reconnect the device.