Hello, I am looking into making an AP that can use DFS frequencies (for VoIP to avoid spectrum congestion) with an USB adapter on a raspberry pi So far we have tried to use an atheros based dongle: Linksys Max-Stream AC600 Dual-Band MU-MIMO USB Adapter (WUSB6100M) Unfortunately the ath10k-usb driver is still very experimental and we were not able to get the dongle to work We also looked to another dongle ID 148f:5572 Ralink Technology, Corp. RT5572 Wireless Adapter iw list says it supports the frequencies with radar detection. The startup of hostapd says the same Allowed channel: mode=2 chan=60 freq=5300 MHz max_tx_power=23 dBm (DFS state = usable) Unfortunately when I start it in AP mode on the channel 60, I get a ressource busy answer when the nl driver send the radar scan message. It happens in the function static int nl80211_start_radar_detection of src/drivers/driver_nl80211.c I tried both with the stock version of raspbian and a fresh pull from Git These are the logs I am getting. =============== DFS support is enabled Completing interface initialization Mode: IEEE 802.11a Channel: 60 Frequency: 5300 MHz DFS 1 channels required radar detection DFS all channels available, (SKIP CAC): no DFS 0 chans unavailable - choose other channel: no wlan1: interface state COUNTRY_UPDATE->DFS DFS start CAC on 5300 MHz wlan1: DFS-CAC-START freq=5300 chan=60 sec_chan=0, width=0, seg0=0, seg1=0, cac_time=60s nl80211: Start radar detection (CAC) 5300 MHz (ht_enabled=1, vht_enabled=0, bandwidth=20 MHz, cf1=5300 MHz, cf2=0 MHz) * freq=5300 * vht_enabled=0 * ht_enabled=1 * sec_channel_offset=0 * channel_type=1 nl80211: Failed to start radar detection: -16 (Device or resource busy) DFS start_dfs_cac() failed, -1 Interface initialization failed wlan1: interface state DFS->DISABLED wlan1: AP-DISABLED wlan1: Unable to setup interface. hostapd_interface_deinit_free(0x13fd8d0) hostapd_interface_deinit_free: num_bss=1 conf->num_bss=1 hostapd_interface_deinit(0x13fd8d0) wlan1: interface state DISABLED->DISABLED hostapd_bss_deinit: deinit bss wlan1 wlan1: Deauthenticate all stations ================== I am ready to help doing further debugging or tests, but I don't know where to start. Do you have suggestions on making DFS work with non ath chipsets ? Thank you Brice _______________________________________________ Hostap mailing list Hostap@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/hostap
