Re: [PATCH] iwlwifi: Fix softirq/hardirq disabling in iwl_pcie_gen2_enqueue_hcmd()
From: Johannes Berg <johannes@sipsolutions.net>
Date: 2021-04-07 07:55:56
Subsystem:
intel wireless wifi link (iwlwifi), the rest · Maintainers:
Miri Korenblit, Linus Torvalds
On Wed, 2021-04-07 at 09:51 +0200, Jiri Kosina wrote:
On Wed, 7 Apr 2021, Heiner Kallweit wrote:quoted
Same fix as in 2800aadc18a6 ("iwlwifi: Fix softirq/hardirq disabling in iwl_pcie_enqueue_hcmd()") is needed for iwl_pcie_gen2_enqueue_hcmd. I get the same lockdep warning on AX210.Makes sense, it's being called from exactly the same contexts.
I'm guessing nobody saw this before because the LEDs stuff is not
supported/used on newer devices :)
Still makes sense though.
Btw, I had a fix for your patch for some devices, see below. Already in
our tree, so Luca will send it on the way, just FYI/review here.
Thanks,
johannes
From: Johannes Berg <redacted>
Date: Tue, 6 Apr 2021 16:50:23 +0200
Subject: [PATCH] [BUGFIX] 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 1ed08f6fb5ae
("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: Johannes Berg <redacted>
---
.../wireless/intel/iwlwifi/pcie/internal.h | 5 ++++
.../net/wireless/intel/iwlwifi/pcie/trans.c | 24 ++++++++++++++++---
drivers/net/wireless/intel/iwlwifi/pcie/tx.c | 4 ++--
3 files changed, 28 insertions(+), 5 deletions(-)
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/internal.h b/drivers/net/wireless/intel/iwlwifi/pcie/internal.h
index 2c2389feb5e1..0b99f0c34111 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/internal.h
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/internal.h@@ -453,6 +453,11 @@ 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 ******************************************************/
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
index f2869fc343e3..bf36fa72f22e 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c@@ -2047,12 +2047,16 @@ 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;
@@ -2137,7 +2141,7 @@ 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; }
@@ -2150,6 +2154,20 @@ out: 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);
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/tx.c b/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
index 0346505351f5..4f6c187eed69 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx.c@@ -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; }
--
2.30.2