On Wed, 2021-04-07 at 09:51 +0200, Jiri Kosina wrote:
> On Wed, 7 Apr 2021, Heiner Kallweit wrote:
>
> > 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 <johannes.berg@xxxxxxxxx>
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 <johannes.berg@xxxxxxxxx>
---
.../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
