Commit c544d89b authored by Johannes Berg's avatar Johannes Berg Committed by Kalle Valo
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iwlwifi: pcie: don't enable BHs with IRQs disabled 



After the fix from Jiri that disabled local IRQs instead of
just BHs (necessary to fix an issue with submitting a command
with IRQs already disabled), there was still a situation in
which we could deep in there enable BHs, if the device config
sets the apmg_wake_up_wa configuration, which is true on all
7000 series devices.

To fix that, but not require reverting commit 1ed08f6f
("iwlwifi: remove flags argument for nic_access"), split up
nic access into a version with BH manipulation to use most
of the time, and without it for this specific case where the
local IRQs are already disabled.

Signed-off-by: default avatarJohannes Berg <johannes.berg@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.20210415164821.d0f2edda1651.I75f762e0bed38914d1300ea198b86dd449b4b206@changeid
parent fa84df70

drivers/net/wireless/intel/iwlwifi/pcie/internal.h

+5 −0
Original line number Diff line number Diff line
@@ -447,6 +447,11 @@ struct iwl_trans 
		      const struct iwl_cfg_trans_params *cfg_trans);

void iwl_trans_pcie_free(struct iwl_trans *trans);



bool __iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans);

#define _iwl_trans_pcie_grab_nic_access(trans)			\

	__cond_lock(nic_access_nobh,				\

		    likely(__iwl_trans_pcie_grab_nic_access(trans)))



/*****************************************************

* RX

******************************************************/

drivers/net/wireless/intel/iwlwifi/pcie/trans.c

+21 −3
Original line number Diff line number Diff line
@@ -1978,12 +1978,16 @@ static void iwl_trans_pcie_removal_wk(struct work_struct *wk) 
	module_put(THIS_MODULE);

}



static bool iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans)

/*

 * This version doesn't disable BHs but rather assumes they're

 * already disabled.

 */

bool __iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans)

{

	int ret;

	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);



	spin_lock_bh(&trans_pcie->reg_lock);

	spin_lock(&trans_pcie->reg_lock);



	if (trans_pcie->cmd_hold_nic_awake)

		goto out;
@@ -2068,7 +2072,7 @@ static bool iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans) 
		}



err:

		spin_unlock_bh(&trans_pcie->reg_lock);

		spin_unlock(&trans_pcie->reg_lock);

		return false;

	}
@@ -2081,6 +2085,20 @@ static bool iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans) 
	return true;

}



static bool iwl_trans_pcie_grab_nic_access(struct iwl_trans *trans)

{

	bool ret;



	local_bh_disable();

	ret = __iwl_trans_pcie_grab_nic_access(trans);

	if (ret) {

		/* keep BHs disabled until iwl_trans_pcie_release_nic_access */

		return ret;

	}

	local_bh_enable();

	return false;

}



static void iwl_trans_pcie_release_nic_access(struct iwl_trans *trans)

{

	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);

drivers/net/wireless/intel/iwlwifi/pcie/tx.c

+2 −2
Original line number Diff line number Diff line
@@ -643,7 +643,7 @@ static int iwl_pcie_set_cmd_in_flight(struct iwl_trans *trans, 
	 * returned. This needs to be done only on NICs that have

	 * apmg_wake_up_wa set (see above.)

	 */

	if (!iwl_trans_grab_nic_access(trans))

	if (!_iwl_trans_pcie_grab_nic_access(trans))

		return -EIO;



	/*
@@ -652,7 +652,7 @@ static int iwl_pcie_set_cmd_in_flight(struct iwl_trans *trans, 
	 * already true, so it's OK to unconditionally set it to true.

	 */

	trans_pcie->cmd_hold_nic_awake = true;

	spin_unlock_bh(&trans_pcie->reg_lock);

	spin_unlock(&trans_pcie->reg_lock);



	return 0;

}