4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mohammed Shafi Shajakhan <mohammed@xxxxxxxxxxxxxxxx> [ Upstream commit a28f6f27a88f047f03f04b9246ca260ebc91455e ] Fetch target operating channel during potential radar detection when the interface is just brought up, but no channel is assigned from userspace. In this scenario rx_channel may not be having a valid pointer hence fetch the target operating channel to avoid warnings as below which can be triggered by the commands with DFS testing over longer run comamnds: iw wlan1 set type mesh ifconfig wlan1 up (valid tgt_oper_chan only) iw wlan1 cac trigger freq 5260 HT20 (valid rx_channel, tgt_oper_chan) iw wlan1 cac trigger freq 5280 HT20 iw wlan1 cac trigger freq 5300 HT20 Once the CAC expires, current channel context will be removed and we are only left with the fallback option of using 'target operating channel' Firmware and driver log: ath: phy1: DFS: radar found on freq=5300: id=1, pri=1125, count=5, count_false=4 ath: phy1: DFS: radar found on freq=5260: id=5, pri=3151, count=6, count_false=11 ath: phy1: DFS: radar found on freq=5280: id=1, pri=1351, count=6, count_false=4 ath: phy1: DFS: radar found on freq=5300: id=1, pri=1125, count=5, count_false=4 ath10k_pci 0001:01:00.0: failed to derive channel for radar pulse, treating as radar ath10k_pci 0001:01:00.0: failed to derive channel for radar pulse, treating as radar Call trace: WARNING: CPU: 1 PID: 2145 at backports-20161201-3.14.77-9ab3068/net/wireless/chan.c:265 cfg80211_set_dfs_state+0x3c/0x88 [cfg80211]() Workqueue: phy1 ieee80211_dfs_radar_detected_work [mac80211] [<c0320770>] (warn_slowpath_null) from [<bf79b90c>] (cfg80211_set_dfs_state+0x3c/0x88 [cfg80211]) [<bf79b90c>] (cfg80211_set_dfs_state [cfg80211]) from [<bf79697c>] (cfg80211_radar_event+0xc4/0x140 [cfg80211]) [<bf79697c>] (cfg80211_radar_event [cfg80211]) from [<bf83c058>] (ieee80211_dfs_radar_detected_work+0xa8/0xb4 [mac80211]) [<bf83c058>] (ieee80211_dfs_radar_detected_work [mac80211]) from [<c0339518>] (process_one_work+0x298/0x4a4) Signed-off-by: Mohammed Shafi Shajakhan <mohammed@xxxxxxxxxxxxxxxx> Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/wireless/ath/ath10k/wmi.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/net/wireless/ath/ath10k/wmi.c +++ b/drivers/net/wireless/ath/ath10k/wmi.c @@ -3638,6 +3638,11 @@ static void ath10k_dfs_radar_report(stru spin_lock_bh(&ar->data_lock); ch = ar->rx_channel; + + /* fetch target operating channel during channel change */ + if (!ch) + ch = ar->tgt_oper_chan; + spin_unlock_bh(&ar->data_lock); if (!ch) {