software wifi access point: hostapd freezes system

Xyne · 2015-05-26 00:32:41

I have some scripts that set up a wifi access point through the laptop's onboard wifi card. Since a few weeks ago the system now freezes when running the hostapd command and I have to power off by holding down the power button:

Here is the hostapd configuration file (taken from the wiki):

ssid=foo
wpa_passphrase=blahblah
interface=wlan0
#bridge=br0
auth_algs=3
# setting this appears to be the problem
channel=7
driver=nl80211
hw_mode=g
logger_stdout=-1
logger_stdout_level=2
max_num_sta=5
rsn_pairwise=CCMP
wpa=2
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP CCMP

I am running the following command

hostapd -d -t -K /path/to/aforementioned/hostapd.conf

The onboard wifi adapter is this well-known POS:

Realtek RTL8188CE 802.11b/g/n WiFi Adapter

The adapter works for regular connections. Tweaking the hostapd.conf file has led me to conclude that the channel parameter is the problem. If I omit it, hostapd simply fails to establish an AP but exits. If I include it, it completely freezes all system input.

Conky seems to keep updating in the background but journalctl -f freezes. The output from hostapd in "-d" and "--dd" mode flies past too quickly to follow and then infinitely prints blank lines.

Up until a few weeks ago this worked without a hitch. Given that this interrupts user input I wonder if it might be a hardware problem (dying card?) but I don't know how to check that. Again, connecting to wifi networks works without any issue (that I have noticed). Could this be related to a recent kernel upgrade?

I'm going to try redirecting the output of hostapd to a file and then using the "magic" sysrq key to sync it before killing the system. If that works I'll post it. Until then, any suggestions of how to debug this would be appreciated.

Arch Linux

#1 2015-05-26 00:32:41

software wifi access point: hostapd freezes system

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