[SRU] [H/OEM-5.10] [PATCH 0/3] Handle Intel Wifi firmware disconnection

[Kai-Heng Feng]

BugLink: https://bugs.launchpad.net/bugs/1922171

[Impact]
Intel Wifi firmware may crash when it's connected to B/G wireless.

[Fix]
There's a new "feature" that when firmware thinks there are too much
noise in the current frequency, it will automatically disconnect
wifi and expect software/OS to change channel/frequency and reconnect.
Otherwise, firmware crashes.

[Test]
[ 2651.943142] wlp0s20f3: associate with 00:24:a5:b5:f8:93 (try 1/3)
[ 2651.951043] wlp0s20f3: RX AssocResp from 00:24:a5:b5:f8:93 (capab=0x421 status=0 aid=1)
[ 2651.962960] wlp0s20f3: associated
[ 2651.966183] IPv6: ADDRCONF(NETDEV_CHANGE): wlp0s20f3: link becomes ready
[ 2651.972582] wlp0s20f3: Driver requested disconnection from AP 00:24:a5:b5:f8:93
[ 2654.641627] wlp0s20f3: authenticate with 00:24:a5:b5:f8:93

Now it's "Driver requested disconnection" instead of firmware crash.

[Where problems could occur]
The first two patches on 80211 only provide new hook and don't bring any
functional change.

The third patch achieves the "feature" by removing cap
IEEE80211_HE_PHY_CAP0_CHANNEL_WIDTH_SET_40MHZ_IN_2G. I am no expert on
80211, but if there's any AP that doesn't support 20MHZ for 2.4G, the
reconnecting may fail.

Johannes Berg (3):
  cfg80211: support immediate reconnect request hint
  mac80211: support driver-based disconnect with reconnect hint
  iwlwifi: mvm: handle CCA-EXT delay firmware notification

 .../wireless/intel/iwlwifi/fw/api/datapath.h  | 86 +++++--------------
 .../net/wireless/intel/iwlwifi/mvm/mac80211.c | 39 +++++++++
 drivers/net/wireless/intel/iwlwifi/mvm/mvm.h  |  3 +
 drivers/net/wireless/intel/iwlwifi/mvm/ops.c  | 68 +++++++++++++++
 .../net/wireless/intel/iwlwifi/mvm/utils.c    | 30 +++++++
 include/net/cfg80211.h                        |  4 +-
 include/net/mac80211.h                        | 11 +++
 include/uapi/linux/nl80211.h                  |  6 ++
 net/mac80211/ieee80211_i.h                    |  4 +-
 net/mac80211/mlme.c                           | 72 ++++++++++++----
 net/mac80211/trace.h                          | 23 ++++-
 net/wireless/mlme.c                           | 26 +++---
 net/wireless/nl80211.c                        | 23 +++--
 net/wireless/nl80211.h                        |  8 +-
 net/wireless/trace.h                          | 12 ++-
 15 files changed, 303 insertions(+), 112 deletions(-)

-- 
2.30.2