4.18-stable review patch. If anyone has any objections, please let me know.
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From: Emmanuel Grumbach emmanuel.grumbach@intel.com
[ Upstream commit 155f7e0441cd121b1e673d465a35e99f4b9b2f0b ]
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: bf8b286f86fc ("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 Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c @@ -1232,12 +1232,15 @@ void __iwl_mvm_mac_stop(struct iwl_mvm * iwl_mvm_del_aux_sta(mvm);
/* - * Clear IN_HW_RESTART flag when stopping the hw (as restart_complete() - * won't be called in this case). + * Clear IN_HW_RESTART and HW_RESTART_REQUESTED flag when stopping the + * hw (as restart_complete() won't be called in this case) and mac80211 + * won't execute the restart. * But make sure to cleanup interfaces that have gone down before/during * HW restart was requested. */ - if (test_and_clear_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status)) + if (test_and_clear_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status) || + test_and_clear_bit(IWL_MVM_STATUS_HW_RESTART_REQUESTED, + &mvm->status)) ieee80211_iterate_interfaces(mvm->hw, 0, iwl_mvm_cleanup_iterator, mvm);