[FS#619] mac80211: AP+11s VIFs broken

[LEDE Bugs]

A new Flyspray task has been opened.  Details are below. 

User who did this - Matthias Schiffer (NeoRaider) 

Attached to Project - LEDE Project
Summary - mac80211: AP+11s VIFs broken
Task Type - Bug Report
Category - Base system
Status - New
Assigned To - 
Operating System - All
Severity - Low
Priority - Medium
Reported Version - Trunk
Due in Version - Undecided
Due Date - Undecided
Details - When two VIFs are configured in AP and 11s mode, the 11s interface won't come up correctly, the channel is unset in the iwinfo output:


# iwinfo
client0   ESSID: "Experimental"
          Access Point: B6:1C:ED:57:10:D0
          Mode: Master  Channel: 1 (2.412 GHz)
          Tx-Power: 16 dBm  Link Quality: unknown/70
          Signal: unknown  Noise: unknown
          Bit Rate: unknown
          Encryption: none
          Type: nl80211  HW Mode(s): 802.11bgn
          Hardware: unknown [Generic MAC80211]
          TX power offset: unknown
          Frequency offset: unknown
          Supports VAPs: yes  PHY name: phy0

mesh0     ESSID: unknown
          Access Point: 00:00:00:00:00:00
          Mode: Mesh Point  Channel: unknown (unknown)
          Tx-Power: 16 dBm  Link Quality: unknown/70
          Signal: unknown  Noise: unknown
          Bit Rate: unknown
          Encryption: unknown
          Type: nl80211  HW Mode(s): 802.11bgn
          Hardware: unknown [Generic MAC80211]
          TX power offset: unknown
          Frequency offset: unknown
          Supports VAPs: yes  PHY name: phy0


As soon as there is a second mesh point and some traffic, the kernel log is spammed with messages like the following:

[   74.509141] ------------[ cut here ]------------
[   74.514193] WARNING: CPU: 0 PID: 10 at compat-wireless-2017-01-31/net/mac80211/ieee80211_i.h:1011 mesh_matches_local+0xb0/0x2f0 [mac80211]()
[   74.527247] Modules linked in: ath9k ath9k_common pppoe ppp_async ath9k_hw ath pppox ppp_generic nf_conntrack_ipv6 mac80211 iptable_nat ipt_REJECT ipt_MASQUERADE cfg80211 xt_time xt_tcpudp xt_state xt_nat xt_multiport xt_mark xt_mac xt_limit xt_conntrack xt_comment xt_TCPMSS xt_REDIRECT xt_LOG xt_CT slhc nf_reject_ipv4 nf_nat_redirect nf_nat_masquerade_ipv4 nf_conntrack_ipv4 nf_nat_ipv4 nf_nat nf_log_ipv4 nf_defrag_ipv6
 nf_defrag_ipv4 nf_conntrack_rtcache nf_conntrack iptable_mangle iptable_filter ip_tables crc_ccitt compat ip6t_REJECT nf_reject_ipv6 nf_log_ipv6 nf_log_common ip6table_mangle ip6table_filter ip6_tables x_tables gpio_button_hotplug
[   74.586877] CPU: 0 PID: 10 Comm: kworker/u2:2 Not tainted 4.4.52 #0
[   74.593455] Workqueue: phy0 ieee80211_ibss_leave [mac80211]
[   74.599212] Stack : 81803410 81878398 00000088 800a7640 8182eac4 8042ee63 803c5ff4 0000000a
          803f13e4 8187dbec 80430000 800a55bc 00000088 800a7640 803cb6e4 80430000
          00000003 8187dbec 80430000 800955d8 00000088 8187dc24 00000000 801f5800
          00000001 801f5800 80e13adc 81b43e00 81b43f00 70687930 00000000 00000000
          00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
          ...
[   74.636246] Call Trace:
[   74.638788] [] show_stack+0x50/0x84
[   74.643318] [] warn_slowpath_common+0xa0/0xd0
[   74.648716] [] warn_slowpath_null+0x18/0x24
[   74.654034] [] mesh_matches_local+0xb0/0x2f0 [mac80211]
[   74.660430] [] mesh_matches_local+0x268/0x2f0 [mac80211]
[   74.666885]
[   74.668433] ---[ end trace 7ec43a5bea41b571 ]---


The mesh0 interface is shown as NO-CARRIER, and obviously, no connection is possible. No other unusual log messages occur.

The issue affects both master (r3680-0ebc681) and the current HEAD of lede-17.01. The 17.01.0 release was fine, so I expect that something in https://git.lede-project.org/?p=source.git;a=commitdiff;h=703515f889124248480f39d65f8704548cbf1c09 broke this. It is not driver-specific, I got reports for ath9k and mt76.

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=619