Commit 96d2bfb7 authored by Shaul Triebitz's avatar Shaul Triebitz Committed by Kalle Valo
Browse files

iwlwifi: mvm: clear IN_D3 after wowlan status cmd 



In D3 resume flow, avoid the following race where sending
packets before updating the sequence number (sequence
number received from the wowlan status command response):
Thread 1:
__iwl_mvm_resume clears IWL_MVM_STATUS_IN_D3 and is cut
by thread 2 before reaching iwl_mvm_query_wakeup_reasons.
Thread 2:
iwl_mvm_mac_itxq_xmit calls iwl_mvm_tx_skb since
IWL_MVM_STATUS_IN_D3 is not set using a wrong sequence number.
Thread 1:
__iwl_mvm_resume continues and calls iwl_mvm_query_wakeup_reasons
updating the sequence number received from the firmware.

The next packet that will be sent now will cause sysassert 0x1096.

Fix the bug by moving 'clear IWL_MVM_STATUS_IN_D3' to after
sending the wowlan status command and updating the sequence
number.

Signed-off-by: default avatarShaul Triebitz <shaul.triebitz@intel.com>
Signed-off-by: default avatarLuca Coelho <luciano.coelho@intel.com>
Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/iwlwifi.20210122144849.fe927ec939c6.I103d3321fb55da7e6c6c51582cfadf94eb8b6c58@changeid
parent 16062c12

drivers/net/wireless/intel/iwlwifi/mvm/d3.c

+3 −3
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause

/*

 * Copyright (C) 2012-2014, 2018-2020 Intel Corporation

 * Copyright (C) 2012-2014, 2018-2021 Intel Corporation

 * Copyright (C) 2013-2015 Intel Mobile Communications GmbH

 * Copyright (C) 2016-2017 Intel Deutschland GmbH

 */
@@ -2032,8 +2032,6 @@ static int __iwl_mvm_resume(struct iwl_mvm *mvm, bool test) 


	mutex_lock(&mvm->mutex);



	clear_bit(IWL_MVM_STATUS_IN_D3, &mvm->status);



	/* get the BSS vif pointer again */

	vif = iwl_mvm_get_bss_vif(mvm);

	if (IS_ERR_OR_NULL(vif))
@@ -2148,6 +2146,8 @@ static int __iwl_mvm_resume(struct iwl_mvm *mvm, bool test) 
			iwl_mvm_d3_disconnect_iter, keep ? vif : NULL);



out:

	clear_bit(IWL_MVM_STATUS_IN_D3, &mvm->status);



	/* no need to reset the device in unified images, if successful */

	if (unified_image && !ret) {

		/* nothing else to do if we already sent D0I3_END_CMD */