Subject: [PATCH] ath11k: fix channel ctx call trace in monitor

Channel context not created in the radio, so that monitor vdev
start failed due to channel context null.

Call Trace:

------------[ cut here ]------------
WARNING: CPU: 1 PID: 3216 at /local/mnt/workspace/periyasa/4_4_ipq6018_27Oct2020/qsdk/build_dir/target-arm_cortex-a7_musl-1.1.16_eabi/linux-ipq_ipq60xx/backports-20200908-4.4.60-9a94b73e75/drivers/net/wireless/ath/ath11k/mac.c:807 ath11k_mac_op_add_chanctx+0x5a0/0x86c [ath11k]()
Modules linked in: ath9k ath9k_common iptable_nat ath9k_hw ath11k_pci ath11k_ahb ath11k ath10k_pci ath10k_core ath nf_nat_pptp nf_nat_ipv4 nf_nat_amanda nf_conntrack_pptp nf_conntrack_ipv4 nf_conntrack_amanda mac80211 ipt_REJECT ipt_MASQUERADE cfg80211 xt_time xt_tcpudp xt_tcpmss
CPU: 0 PID: 3216 Comm: ifconfig Not tainted 4.4.60 #11
Hardware name: Generic DT based system
[<80116dac>] (unwind_backtrace) from [<80113700>] (show_stack+0x10/0x14)
[<80113700>] (show_stack) from [<80317eb4>] (dump_stack+0x7c/0x9c)
[<80317eb4>] (dump_stack) from [<801239e0>] (warn_slowpath_common+0x80/0xac)
[<801239e0>] (warn_slowpath_common) from [<80123a9c>] (warn_slowpath_null+0x18/0x20)
[<80123a9c>] (warn_slowpath_null) from [<c5fab68c>] (ath11k_mac_op_add_chanctx+0x5a0/0x86c [ath11k])
[<c5fab68c>] (ath11k_mac_op_add_chanctx [ath11k]) from [<c5fad764>] (ath11k_mac_op_unassign_vif_chanctx+0x368/0x64c [ath11k])
[<c5fad764>] (ath11k_mac_op_unassign_vif_chanctx [ath11k]) from [<c5fadda0>] (ath11k_mac_op_config+0x78/0x1c4 [ath11k])
[<c5fadda0>] (ath11k_mac_op_config [ath11k]) from [<c5bb5974>] (ieee80211_hw_config+0x23c/0x2c0 [mac80211])
[<c5bb5974>] (ieee80211_hw_config [mac80211]) from [<c5bc9df4>] (ieee80211_do_open+0x688/0x8cc [mac80211])
[<c5bc9df4>] (ieee80211_do_open [mac80211]) from [<8054969c>] (__dev_open+0xa0/0xf4)
[<8054969c>] (__dev_open) from [<805498e8>] (__dev_change_flags+0x8c/0x130)
[<805498e8>] (__dev_change_flags) from [<805499a4>] (dev_change_flags+0x18/0x48)
[<805499a4>] (dev_change_flags) from [<805acb10>] (devinet_ioctl+0x2d8/0x648)
[<805acb10>] (devinet_ioctl) from [<8052e5ac>] (sock_ioctl+0x224/0x278)
[<8052e5ac>] (sock_ioctl) from [<801f3204>] (do_vfs_ioctl+0x4f0/0x5b0)
[<801f3204>] (do_vfs_ioctl) from [<801f32f8>] (SyS_ioctl+0x34/0x5c)
[<801f32f8>] (SyS_ioctl) from [<80101b80>] (ret_fast_syscall+0x0/0x34)
---[ end trace 9a32f5c3b9a0b9bd ]---
ath11k c000000.wifi: failed to start monitor vdev: -2

Signed-off-by: Karthikeyan Periyasamy <periyasa@codeaurora.org>
---
--- a/drivers/net/wireless/ath/ath11k/mac.c
+++ b/drivers/net/wireless/ath/ath11k/mac.c
@@ -766,25 +766,19 @@ static inline int ath11k_mac_vdev_setup_
 	return ar->last_wmi_vdev_start_status ? -EINVAL : 0;
 }
 
-static int ath11k_mac_monitor_vdev_start(struct ath11k *ar, int vdev_id)
+static int ath11k_mac_monitor_vdev_start(struct ath11k *ar, int vdev_id,
+					 struct cfg80211_chan_def *chandef)
 {
 	struct vdev_up_params params = {
 		.vdev_id = vdev_id,
 		.bssid = ar->mac_addr,
 	};
-	struct cfg80211_chan_def *chandef = NULL;
 	struct ieee80211_channel *channel = NULL;
 	struct wmi_vdev_start_req_arg arg = {};
 	int ret = 0;
 
 	lockdep_assert_held(&ar->conf_mutex);
 
-	ieee80211_iter_chan_contexts_atomic(ar->hw,
-					    ath11k_mac_get_any_chandef_iter,
-					    &chandef);
-
-	if (WARN_ON_ONCE(!chandef))
-		return -ENOENT;
 	channel = chandef->chan;
 	arg.vdev_id = vdev_id;
 	arg.channel.freq = channel->center_freq;
@@ -979,6 +973,7 @@ static int ath11k_mac_monitor_vdev_delet
 
 static int ath11k_mac_monitor_start(struct ath11k *ar)
 {
+	struct cfg80211_chan_def *chandef = NULL;
 	int ret;
 
 	lockdep_assert_held(&ar->conf_mutex);
@@ -986,7 +981,13 @@ static int ath11k_mac_monitor_start(stru
 	if (ar->monitor_started)
 		return 0;
 
-	ret = ath11k_mac_monitor_vdev_start(ar, ar->monitor_vdev_id);
+	ieee80211_iter_chan_contexts_atomic(ar->hw,
+					    ath11k_mac_get_any_chandef_iter,
+					    &chandef);
+	if (!chandef)
+		return 0;
+
+	ret = ath11k_mac_monitor_vdev_start(ar, ar->monitor_vdev_id, chandef);
 	if (ret) {
 		ath11k_warn(ar->ab, "failed to start monitor vdev: %d\n", ret);
 		ath11k_mac_monitor_vdev_delete(ar);