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Emmanuel Grumbach 155f7e0441 iwlwifi: mvm: clear HW_RESTART_REQUESTED when stopping the interface
Fix a bug that happens in the following scenario:
1) suspend without WoWLAN
2) mac80211 calls drv_stop because of the suspend
3) __iwl_mvm_mac_stop deallocates the aux station
4) during drv_stop the firmware crashes
5) iwlmvm:
	* sets IWL_MVM_STATUS_HW_RESTART_REQUESTED
	* asks mac80211 to kick the restart flow
6) mac80211 puts the restart worker into a freezable
   queue which means that the worker will not run for now
   since the workqueue is already frozen
7) ...
8) resume
9) mac80211 runs ieee80211_reconfig as part of the resume
10) mac80211 detects that a restart flow has been requested
    and that we are now resuming from suspend and cancels
    the restart worker
11) mac80211 calls drv_start()
12) __iwl_mvm_mac_start checks that IWL_MVM_STATUS_HW_RESTART_REQUESTED
    clears it, sets IWL_MVM_STATUS_IN_HW_RESTART and calls
    iwl_mvm_restart_cleanup()
13) iwl_fw_error_dump gets called and accesses the device
    to get debug data
14) iwl_mvm_up adds the aux station
15) iwl_mvm_add_aux_sta() allocates an internal station for
    the aux station
16) iwl_mvm_allocate_int_sta() tests IWL_MVM_STATUS_IN_HW_RESTART
    and doesn't really allocate a station ID for the aux
    station
17) a new queue is added for the aux station

Note that steps from 5 to 9 aren't really part of the
problem but were described for the sake of completeness.

Once the iwl_mvm_mac_stop() is called, the device is not
accessible, meaning that step 12) can't succeed and we'll
see the following:

drivers/net/wireless/intel/iwlwifi/pcie/trans.c:2122 iwl_trans_pcie_grab_nic_access+0xc0/0x1d6 [iwlwifi]()
Timeout waiting for hardware access (CSR_GP_CNTRL 0x080403d8)
Call Trace:
[<ffffffffc03e6ad3>] iwl_trans_pcie_grab_nic_access+0xc0/0x1d6 [iwlwifi]
[<ffffffffc03e6a13>] iwl_trans_pcie_dump_regs+0x3fd/0x3fd [iwlwifi]
[<ffffffffc03dad42>] iwl_fw_error_dump+0x4f5/0xe8b [iwlwifi]
[<ffffffffc04bd43e>] __iwl_mvm_mac_start+0x5a/0x21a [iwlmvm]
[<ffffffffc04bd6d2>] iwl_mvm_mac_start+0xd4/0x103 [iwlmvm]
[<ffffffffc042d378>] drv_start+0xa1/0xc5 [iwl7000_mac80211]
[<ffffffffc045a339>] ieee80211_reconfig+0x145/0xf50 [mac80211]
[<ffffffffc044788b>] ieee80211_resume+0x62/0x66 [mac80211]
[<ffffffffc0366c5b>] wiphy_resume+0xa9/0xc6 [cfg80211]

The station id of the aux station is set to 0xff in step 3
and because we don't really allocate a new station id for
the auxliary station (as explained in 16), we end up sending
a command to the firmware asking to connect the queue
to station id 0xff. This makes the firmware crash with the
following information:

0x00002093 | ADVANCED_SYSASSERT
0x000002F0 | trm_hw_status0
0x00000000 | trm_hw_status1
0x00000B38 | branchlink2
0x0001978C | interruptlink1
0x00000000 | interruptlink2
0xFF080501 | data1
0xDEADBEEF | data2
0xDEADBEEF | data3
Firmware error during reconfiguration - reprobe!
FW error in SYNC CMD SCD_QUEUE_CFG

Fix this by clearing IWL_MVM_STATUS_HW_RESTART_REQUESTED
in iwl_mvm_mac_stop(). We won't be able to collect debug
data anyway and when we will brought up again, we will
have a clean state from the firmware perspective.
Since we won't have IWL_MVM_STATUS_IN_HW_RESTART set in
step 12) we won't get to the 2093 ASSERT either.

Fixes: bf8b286f86 ("iwlwifi: mvm: defer setting IWL_MVM_STATUS_IN_HW_RESTART")
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
2018-10-06 10:25:45 +03:00
arch Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-09-25 10:35:29 -07:00
block block: use nanosecond resolution for iostat 2018-09-21 20:26:59 -06:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto DMAengine updates for v4.19-rc1 2018-08-18 15:55:59 -07:00
Documentation Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2018-10-01 22:31:17 -07:00
drivers iwlwifi: mvm: clear HW_RESTART_REQUESTED when stopping the interface 2018-10-06 10:25:45 +03:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs This pull request contains fixes for UBIFS: 2018-09-21 15:29:44 +02:00
include tls: Add support for inplace records encryption 2018-10-02 23:03:47 -07:00
init Kbuild updates for v4.19 (2nd) 2018-08-25 13:40:38 -07:00
ipc ipc/shm: properly return EIDRM in shm_lock() 2018-09-04 16:45:02 -07:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2018-09-25 20:29:38 -07:00
lib netlink: add validation function to policy 2018-10-01 23:05:31 -07:00
LICENSES LICENSES: Add Linux-OpenIB license text 2018-04-27 16:41:53 -06:00
mm mm: slowly shrink slabs with a relatively small number of objects 2018-09-20 22:01:11 +02:00
net tls: Add support for inplace records encryption 2018-10-02 23:03:47 -07:00
samples samples/bpf: fix compilation failure 2018-09-21 22:51:16 +02:00
scripts linux-kselftest-4.19-rc5 2018-09-17 07:24:28 +02:00
security Revert "uapi/linux/keyctl.h: don't use C++ reserved keyword as a struct member name" 2018-09-25 13:28:58 +02:00
sound ASoC: Fixes for v4.19 2018-09-17 18:59:21 +02:00
tools selftests/tls: Fix recv(MSG_PEEK) & splice() test cases 2018-10-01 23:18:15 -07:00
usr initramfs: move gen_initramfs_list.sh from scripts/ to usr/ 2018-08-22 23:21:44 +09:00
virt KVM: Remove obsolete kvm_unmap_hva notifier backend 2018-09-07 15:06:02 +02:00
.clang-format clang-format: Set IndentWrappedFunctionNames false 2018-08-01 18:38:51 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap libnvdimm-for-4.19_misc 2018-08-25 18:13:10 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS 9p: remove Ron Minnich from MAINTAINERS 2018-08-17 16:20:26 -07:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS net: dsa: lantiq: Fix path in MAINTAINERS file 2018-10-02 22:58:40 -07:00
Makefile Linux 4.19-rc5 2018-09-23 19:15:18 +02:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.