Hi all, I have spend several days debugging ath6kl driver to work well in AP mode for 802.11n (i.e. when ieee80211n=1 in hostapd.conf). With this setting hostapd was constantly failing with: nl80211: Failed to set channel (freq=2442): -22 (Invalid argument), please refer to the http://www.spinics.net/lists/linux-wireless/msg113987.html I am using AR9374 based USB dongle, UB134 reference design (AR6004 firmware, i.e. hw1.3, http://git.kernel.org/cgit/linux/kernel/git/firmware/linux-firmware.git/tree/ath6k/AR6004/hw1.3). On fw load driver outputs the message: ath6kl: ar6004 hw 1.3 usb fw 3.5.0.2356 api 3. Ftrace in the kernel lead me to the cfg80211_chandef_usable() (http://lxr.free-electrons.com/source/net/wireless/chan.c#L47), which was failing on the checks of ht_cap->ht_supported. For some reasons these were FALSE, even that they should be present. Further inspection leads to ath6kl_cfg80211_init(), and especially this check of ATH6KL_FW_CAPABILITY_RSN_CAP_OVERRIDE: https://github.com/kvalo/ath/blob/master/drivers/net/wireless/ath/ath6kl/cfg80211.c#L3767 which fails, and thus HT is not supported anymore, breaking hostapd and making it impossible to put the dongle in the AP 802.11n mode. Previous to this check, ht was set to TRUE on WMI_11AGN_CAP case (https://github.com/kvalo/ath/blob/master/drivers/net/wireless/ath/ath6kl/cfg80211.c#L3750), which I verified with printk. Googling aroud led me to these patches: http://permalink.gmane.org/gmane.linux.kernel.wireless.general/89741 http://www.spinics.net/lists/linux-wireless/msg87931.html Commenting out these checks I was able to put the dongle in both 802.11gn and 802.11an in AP mode without encryption and with WPAm but not without WPA2 (probably because of 4-way handshaking mentioned in the comments). Can we characterize this behavior like a bug in the firmware, or is this limitation is intentional (which I doubt)? Bug summary: ATH6KL_FW_CAPABILITY_RSN_CAP_OVERRIDE not set in latest linux-firmware, AP mode in 802.11n not possible, breaks hostapd when ieee80211n=1 ATH chipset: AR9374 based USB dongle, UB134 reference design FW: ar6004 hw 1.3 usb fw 3.5.0.2356 api 3 hostpad: latest stable, hostapd-2.0 linux-firmware: latest from the http://git.kernel.org/cgit/linux/kernel/git/firmware/linux-firmware.git (git hash 7d0c7a8cfd78388d90cc784a185b19dcbdbce824) Best regards, Drasko -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
