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From: Karthikeyan Periyasamy <quic_periyasa@quicinc.com>
To: <ath12k@lists.infradead.org>
CC: <linux-wireless@vger.kernel.org>,
        Karthikeyan Periyasamy
	<quic_periyasa@quicinc.com>
Subject: [PATCH 2/3] wifi: ath12k: Refactor hardware recovery synchronous
Date: Tue, 30 Jan 2024 11:38:37 +0530
Message-ID: <20240130060838.3895599-3-quic_periyasa@quicinc.com>
In-Reply-To: <20240130060838.3895599-1-quic_periyasa@quicinc.com>
References: <20240130060838.3895599-1-quic_periyasa@quicinc.com>
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Currently, in multi wiphy models, radio/link level synchronization is
sufficient for MAC hardware (ieee80211_hw) reconfigure/recovery procedures
since each radio/link is exposed as a MAC hardware (ieee80211_hw). However,
in single wiphy models, multiple radio/links is exposed as a MAC hardware
(ieee80211_hw) through the driver hardware abstraction (ath12k_hw) layer.
In such scenario, we need synchronization between the reconfigure/recovery
callback operations (i.e., ath12k_core_post_reconfigure_recovery(),
ieee80211_ops->start(), ieee80211_ops->reconfig_complete(),
ieee80211_ops->stop()) at the driver hardware abstraction (ath12k_hw) layer
instead of radio/link (ath12k) layer. Therefore, introduce a new mutex in
the ath12k_hw layer. This approach ensures compatibility of the hardware
recovery procedure with both multi wiphy models and future single wiphy
models.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.0.1-00029-QCAHKSWPL_SILICONZ-1

Signed-off-by: Karthikeyan Periyasamy <quic_periyasa@quicinc.com>
---
 drivers/net/wireless/ath/ath12k/core.c |  4 ++++
 drivers/net/wireless/ath/ath12k/core.h |  5 +++++
 drivers/net/wireless/ath/ath12k/mac.c  | 26 ++++++++++++++++++++++----
 3 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ath/ath12k/core.c b/drivers/net/wireless/ath/ath12k/core.c
index feca204b82b9..4ea5eacc1342 100644
--- a/drivers/net/wireless/ath/ath12k/core.c
+++ b/drivers/net/wireless/ath/ath12k/core.c
@@ -978,6 +978,8 @@ static void ath12k_core_post_reconfigure_recovery(struct ath12k_base *ab)
 		if (!ah)
 			continue;
 
+		mutex_lock(&ah->conf_mutex);
+
 		for (j = 0, restart_count = 0; j < ah->num_radio; j++) {
 			ar = &ah->radio[j];
 			if (ar->state == ATH12K_STATE_OFF)
@@ -1012,6 +1014,8 @@ static void ath12k_core_post_reconfigure_recovery(struct ath12k_base *ab)
 		/* Restart after all the link/radio got restart */
 		if (restart_count == ah->num_radio)
 			ieee80211_restart_hw(ah->hw);
+
+		mutex_unlock(&ah->conf_mutex);
 	}
 
 	complete(&ab->driver_recovery);
diff --git a/drivers/net/wireless/ath/ath12k/core.h b/drivers/net/wireless/ath/ath12k/core.h
index 5c6c1e2eddb6..660c1b260201 100644
--- a/drivers/net/wireless/ath/ath12k/core.h
+++ b/drivers/net/wireless/ath/ath12k/core.h
@@ -600,7 +600,12 @@ struct ath12k {
 struct ath12k_hw {
 	struct ieee80211_hw *hw;
 
+	/* To synchronize hardware restart operation */
+	struct mutex conf_mutex;
+
 	u8 num_radio;
+
+	/* Keep last */
 	struct ath12k radio[] __aligned(sizeof(void *));
 };
 
diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
index 1b465f7fed7f..4c9a591778a2 100644
--- a/drivers/net/wireless/ath/ath12k/mac.c
+++ b/drivers/net/wireless/ath/ath12k/mac.c
@@ -5120,10 +5120,13 @@ static void ath12k_mac_wait_reconfigure(struct ath12k_base *ab)
 
 static int ath12k_mac_start(struct ath12k *ar)
 {
+	struct ath12k_hw *ah = ar->ah;
 	struct ath12k_base *ab = ar->ab;
 	struct ath12k_pdev *pdev = ar->pdev;
 	int ret;
 
+	lockdep_assert_held(&ah->conf_mutex);
+
 	mutex_lock(&ar->conf_mutex);
 
 	switch (ar->state) {
@@ -5247,14 +5250,16 @@ static int ath12k_mac_op_start(struct ieee80211_hw *hw)
 
 	ath12k_mac_drain_tx(ar);
 
+	mutex_lock(&ah->conf_mutex);
+
 	ret = ath12k_mac_start(ar);
-	if (ret) {
+	if (ret)
 		ath12k_err(ab, "fail to start mac operations in pdev idx %d ret %d\n",
 			   ar->pdev_idx, ret);
-		return ret;
-	}
 
-	return 0;
+	mutex_unlock(&ah->conf_mutex);
+
+	return ret;
 }
 
 int ath12k_mac_rfkill_config(struct ath12k *ar)
@@ -5316,9 +5321,12 @@ int ath12k_mac_rfkill_enable_radio(struct ath12k *ar, bool enable)
 
 static void ath12k_mac_stop(struct ath12k *ar)
 {
+	struct ath12k_hw *ah = ar->ah;
 	struct htt_ppdu_stats_info *ppdu_stats, *tmp;
 	int ret;
 
+	lockdep_assert_held(&ah->conf_mutex);
+
 	mutex_lock(&ar->conf_mutex);
 	ret = ath12k_mac_config_mon_status_default(ar, false);
 	if (ret && (ret != -EOPNOTSUPP))
@@ -5354,7 +5362,11 @@ static void ath12k_mac_op_stop(struct ieee80211_hw *hw)
 
 	ath12k_mac_drain_tx(ar);
 
+	mutex_lock(&ah->conf_mutex);
+
 	ath12k_mac_stop(ar);
+
+	mutex_unlock(&ah->conf_mutex);
 }
 
 static u8
@@ -7119,6 +7131,8 @@ ath12k_mac_op_reconfig_complete(struct ieee80211_hw *hw,
 	if (reconfig_type != IEEE80211_RECONFIG_TYPE_RESTART)
 		return;
 
+	mutex_lock(&ah->conf_mutex);
+
 	for (i = 0; i < ah->num_radio; i++) {
 		ar = &ah->radio[i];
 
@@ -7179,6 +7193,8 @@ ath12k_mac_op_reconfig_complete(struct ieee80211_hw *hw,
 
 		mutex_unlock(&ar->conf_mutex);
 	}
+
+	mutex_unlock(&ah->conf_mutex);
 }
 
 static void
@@ -7925,6 +7941,8 @@ static struct ath12k_hw *ath12k_mac_hw_allocate(struct ath12k_base *ab,
 	ah->hw = hw;
 	ah->num_radio = num_pdev_map;
 
+	mutex_init(&ah->conf_mutex);
+
 	for (i = 0; i < num_pdev_map; i++) {
 		ab = pdev_map[i].ab;
 		pdev_idx = pdev_map[i].pdev_idx;
-- 
2.34.1