linux-kernel - [PATCH v2 04/10] rtw88: Drop coex mutex

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Date:   Mon, 30 May 2022 15:54:51 +0200
From:   Sascha Hauer <s.hauer@...gutronix.de>
To:     linux-wireless@...r.kernel.org
Cc:     Neo Jou <neojou@...il.com>, Hans Ulli Kroll <linux@...i-kroll.de>,
        Ping-Ke Shih <pkshih@...ltek.com>,
        Yan-Hsuan Chuang <tony0620emma@...il.com>,
        Kalle Valo <kvalo@...nel.org>, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Martin Blumenstingl <martin.blumenstingl@...glemail.com>,
        kernel@...gutronix.de, Johannes Berg <johannes@...solutions.net>,
        Sascha Hauer <s.hauer@...gutronix.de>
Subject: [PATCH v2 04/10] rtw88: Drop coex mutex

coex->mutex is used in rtw_coex_info_request() only. Most callers of this
function hold rtwdev->mutex already, except for one callsite in the
debugfs code. The debugfs code alone doesn't justify the extra lock, so
acquire rtwdev->mutex there as well and drop the now unnecessary
spinlock.

Signed-off-by: Sascha Hauer <s.hauer@...gutronix.de>
---
 drivers/net/wireless/realtek/rtw88/coex.c  | 3 +--
 drivers/net/wireless/realtek/rtw88/debug.c | 2 ++
 drivers/net/wireless/realtek/rtw88/main.c  | 2 --
 drivers/net/wireless/realtek/rtw88/main.h  | 2 --
 4 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtw88/coex.c b/drivers/net/wireless/realtek/rtw88/coex.c
index cac053f485c3b..b156f8c48ffbb 100644
--- a/drivers/net/wireless/realtek/rtw88/coex.c
+++ b/drivers/net/wireless/realtek/rtw88/coex.c
@@ -633,7 +633,7 @@ static struct sk_buff *rtw_coex_info_request(struct rtw_dev *rtwdev,
 	struct rtw_coex *coex = &rtwdev->coex;
 	struct sk_buff *skb_resp = NULL;
 
-	mutex_lock(&coex->mutex);
+	lockdep_assert_held(&rtwdev->mutex);
 
 	rtw_fw_query_bt_mp_info(rtwdev, req);
 
@@ -650,7 +650,6 @@ static struct sk_buff *rtw_coex_info_request(struct rtw_dev *rtwdev,
 	}
 
 out:
-	mutex_unlock(&coex->mutex);
 	return skb_resp;
 }
 
diff --git a/drivers/net/wireless/realtek/rtw88/debug.c b/drivers/net/wireless/realtek/rtw88/debug.c
index 79939aa6b752c..1453a32ea3ef0 100644
--- a/drivers/net/wireless/realtek/rtw88/debug.c
+++ b/drivers/net/wireless/realtek/rtw88/debug.c
@@ -842,7 +842,9 @@ static int rtw_debugfs_get_coex_info(struct seq_file *m, void *v)
 	struct rtw_debugfs_priv *debugfs_priv = m->private;
 	struct rtw_dev *rtwdev = debugfs_priv->rtwdev;
 
+	mutex_lock(&rtwdev->mutex);
 	rtw_coex_display_coex_info(rtwdev, m);
+	mutex_unlock(&rtwdev->mutex);
 
 	return 0;
 }
diff --git a/drivers/net/wireless/realtek/rtw88/main.c b/drivers/net/wireless/realtek/rtw88/main.c
index baf4d29fde678..5afb8bef9696a 100644
--- a/drivers/net/wireless/realtek/rtw88/main.c
+++ b/drivers/net/wireless/realtek/rtw88/main.c
@@ -1998,7 +1998,6 @@ int rtw_core_init(struct rtw_dev *rtwdev)
 	spin_lock_init(&rtwdev->tx_report.q_lock);
 
 	mutex_init(&rtwdev->mutex);
-	mutex_init(&rtwdev->coex.mutex);
 	mutex_init(&rtwdev->hal.tx_power_mutex);
 
 	init_waitqueue_head(&rtwdev->coex.wait);
@@ -2066,7 +2065,6 @@ void rtw_core_deinit(struct rtw_dev *rtwdev)
 	}
 
 	mutex_destroy(&rtwdev->mutex);
-	mutex_destroy(&rtwdev->coex.mutex);
 	mutex_destroy(&rtwdev->hal.tx_power_mutex);
 }
 EXPORT_SYMBOL(rtw_core_deinit);
diff --git a/drivers/net/wireless/realtek/rtw88/main.h b/drivers/net/wireless/realtek/rtw88/main.h
index 619ee6e8d2807..fc27066a67a72 100644
--- a/drivers/net/wireless/realtek/rtw88/main.h
+++ b/drivers/net/wireless/realtek/rtw88/main.h
@@ -1507,8 +1507,6 @@ struct rtw_coex_stat {
 };
 
 struct rtw_coex {
-	/* protects coex info request section */
-	struct mutex mutex;
 	struct sk_buff_head queue;
 	wait_queue_head_t wait;
 
-- 
2.30.2