linux-wireless.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Johannes Berg <johannes@sipsolutions.net>
To: linux-wireless@vger.kernel.org
Cc: regressions@lists.linux.dev,
	Linus Lotz <register+kernelbugzilla@lotz.li>,
	Darrell Enns <darrell@darrellenns.com>,
	Johannes Berg <johannes.berg@intel.com>
Subject: [RFC PATCH] wifi: iwlwifi: pcie: don't synchronize IRQs from IRQ
Date: Wed,  6 Dec 2023 21:52:07 +0100	[thread overview]
Message-ID: <20231206215211.95907305c9b2.Iadfe154d6248e7f9dfd69522e5429dbbd72925d7@changeid> (raw)
In-Reply-To: <af62295b-b757-49ec-83ce-9d3ef93e24af@leemhuis.info>

From: Johannes Berg <johannes.berg@intel.com>

On older devices (before unified image!) we can end up calling
stop_device from an rfkill interrupt. However, in stop_device
we attempt to synchronize IRQs, which then of course deadlocks.

Avoid this by checking the context, if running from the IRQ
thread then don't synchronize. This wouldn't be correct on a
new device since RSS is supported, but older devices only have
a single interrupt/queue.

Fixes: 37fb29bd1f90 ("wifi: iwlwifi: pcie: synchronize IRQs before NAPI")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 .../net/wireless/intel/iwlwifi/pcie/internal.h  |  4 ++--
 drivers/net/wireless/intel/iwlwifi/pcie/rx.c    |  8 ++++----
 drivers/net/wireless/intel/iwlwifi/pcie/trans.c | 17 +++++++++--------
 3 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/internal.h b/drivers/net/wireless/intel/iwlwifi/pcie/internal.h
index 56def20374f3..7805a42948af 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/internal.h
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/internal.h
@@ -770,7 +770,7 @@ static inline void iwl_enable_rfkill_int(struct iwl_trans *trans)
 	}
 }
 
-void iwl_pcie_handle_rfkill_irq(struct iwl_trans *trans);
+void iwl_pcie_handle_rfkill_irq(struct iwl_trans *trans, bool from_irq);
 
 static inline bool iwl_is_rfkill_set(struct iwl_trans *trans)
 {
@@ -817,7 +817,7 @@ static inline bool iwl_pcie_dbg_on(struct iwl_trans *trans)
 	return (trans->dbg.dest_tlv || iwl_trans_dbg_ini_valid(trans));
 }
 
-void iwl_trans_pcie_rf_kill(struct iwl_trans *trans, bool state);
+void iwl_trans_pcie_rf_kill(struct iwl_trans *trans, bool state, bool from_irq);
 void iwl_trans_pcie_dump_regs(struct iwl_trans *trans);
 
 #ifdef CONFIG_IWLWIFI_DEBUGFS
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
index 146bc7bd14fb..a0d10df0c11a 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
@@ -1783,7 +1783,7 @@ static u32 iwl_pcie_int_cause_ict(struct iwl_trans *trans)
 	return inta;
 }
 
-void iwl_pcie_handle_rfkill_irq(struct iwl_trans *trans)
+void iwl_pcie_handle_rfkill_irq(struct iwl_trans *trans, bool from_irq)
 {
 	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 	struct isr_statistics *isr_stats = &trans_pcie->isr_stats;
@@ -1807,7 +1807,7 @@ void iwl_pcie_handle_rfkill_irq(struct iwl_trans *trans)
 	isr_stats->rfkill++;
 
 	if (prev != report)
-		iwl_trans_pcie_rf_kill(trans, report);
+		iwl_trans_pcie_rf_kill(trans, report, from_irq);
 	mutex_unlock(&trans_pcie->mutex);
 
 	if (hw_rfkill) {
@@ -1947,7 +1947,7 @@ irqreturn_t iwl_pcie_irq_handler(int irq, void *dev_id)
 
 	/* HW RF KILL switch toggled */
 	if (inta & CSR_INT_BIT_RF_KILL) {
-		iwl_pcie_handle_rfkill_irq(trans);
+		iwl_pcie_handle_rfkill_irq(trans, true);
 		handled |= CSR_INT_BIT_RF_KILL;
 	}
 
@@ -2370,7 +2370,7 @@ irqreturn_t iwl_pcie_irq_msix_handler(int irq, void *dev_id)
 
 	/* HW RF KILL switch toggled */
 	if (inta_hw & MSIX_HW_INT_CAUSES_REG_RF_KILL)
-		iwl_pcie_handle_rfkill_irq(trans);
+		iwl_pcie_handle_rfkill_irq(trans, true);
 
 	if (inta_hw & MSIX_HW_INT_CAUSES_REG_HW_ERR) {
 		IWL_ERR(trans,
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
index a468e5efeecd..f43a8923af9e 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
@@ -1082,7 +1082,7 @@ bool iwl_pcie_check_hw_rf_kill(struct iwl_trans *trans)
 	report = test_bit(STATUS_RFKILL_OPMODE, &trans->status);
 
 	if (prev != report)
-		iwl_trans_pcie_rf_kill(trans, report);
+		iwl_trans_pcie_rf_kill(trans, report, false);
 
 	return hw_rfkill;
 }
@@ -1237,7 +1237,7 @@ static void iwl_pcie_init_msix(struct iwl_trans_pcie *trans_pcie)
 	trans_pcie->hw_mask = trans_pcie->hw_init_mask;
 }
 
-static void _iwl_trans_pcie_stop_device(struct iwl_trans *trans)
+static void _iwl_trans_pcie_stop_device(struct iwl_trans *trans, bool from_irq)
 {
 	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 
@@ -1264,7 +1264,8 @@ static void _iwl_trans_pcie_stop_device(struct iwl_trans *trans)
 	if (test_and_clear_bit(STATUS_DEVICE_ENABLED, &trans->status)) {
 		IWL_DEBUG_INFO(trans,
 			       "DEVICE_ENABLED bit was set and is now cleared\n");
-		iwl_pcie_synchronize_irqs(trans);
+		if (!from_irq)
+			iwl_pcie_synchronize_irqs(trans);
 		iwl_pcie_rx_napi_sync(trans);
 		iwl_pcie_tx_stop(trans);
 		iwl_pcie_rx_stop(trans);
@@ -1454,7 +1455,7 @@ void iwl_trans_pcie_handle_stop_rfkill(struct iwl_trans *trans,
 		clear_bit(STATUS_RFKILL_OPMODE, &trans->status);
 	}
 	if (hw_rfkill != was_in_rfkill)
-		iwl_trans_pcie_rf_kill(trans, hw_rfkill);
+		iwl_trans_pcie_rf_kill(trans, hw_rfkill, false);
 }
 
 static void iwl_trans_pcie_stop_device(struct iwl_trans *trans)
@@ -1469,12 +1470,12 @@ static void iwl_trans_pcie_stop_device(struct iwl_trans *trans)
 	mutex_lock(&trans_pcie->mutex);
 	trans_pcie->opmode_down = true;
 	was_in_rfkill = test_bit(STATUS_RFKILL_OPMODE, &trans->status);
-	_iwl_trans_pcie_stop_device(trans);
+	_iwl_trans_pcie_stop_device(trans, false);
 	iwl_trans_pcie_handle_stop_rfkill(trans, was_in_rfkill);
 	mutex_unlock(&trans_pcie->mutex);
 }
 
-void iwl_trans_pcie_rf_kill(struct iwl_trans *trans, bool state)
+void iwl_trans_pcie_rf_kill(struct iwl_trans *trans, bool state, bool from_irq)
 {
 	struct iwl_trans_pcie __maybe_unused *trans_pcie =
 		IWL_TRANS_GET_PCIE_TRANS(trans);
@@ -1487,7 +1488,7 @@ void iwl_trans_pcie_rf_kill(struct iwl_trans *trans, bool state)
 		if (trans->trans_cfg->gen2)
 			_iwl_trans_pcie_gen2_stop_device(trans);
 		else
-			_iwl_trans_pcie_stop_device(trans);
+			_iwl_trans_pcie_stop_device(trans, from_irq);
 	}
 }
 
@@ -2887,7 +2888,7 @@ static ssize_t iwl_dbgfs_rfkill_write(struct file *file,
 	IWL_WARN(trans, "changing debug rfkill %d->%d\n",
 		 trans_pcie->debug_rfkill, new_value);
 	trans_pcie->debug_rfkill = new_value;
-	iwl_pcie_handle_rfkill_irq(trans);
+	iwl_pcie_handle_rfkill_irq(trans, false);
 
 	return count;
 }
-- 
2.43.0


  parent reply	other threads:[~2023-12-06 20:52 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-30  8:23 Fwd: iwlwifi: rfkill locking up kernel 6.5.12, 6.6.2 Bagas Sanjaya
2023-12-02  6:07 ` Linux regression tracking (Thorsten Leemhuis)
2023-12-04  8:12   ` Thorsten Leemhuis
2023-12-06 20:52   ` Johannes Berg [this message]
2023-12-23  9:31 ` Linux regression tracking #update (Thorsten Leemhuis)

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20231206215211.95907305c9b2.Iadfe154d6248e7f9dfd69522e5429dbbd72925d7@changeid \
    --to=johannes@sipsolutions.net \
    --cc=darrell@darrellenns.com \
    --cc=johannes.berg@intel.com \
    --cc=linux-wireless@vger.kernel.org \
    --cc=register+kernelbugzilla@lotz.li \
    --cc=regressions@lists.linux.dev \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).