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From:   Sascha Hauer <s.hauer@pengutronix.de>
To:     linux-wireless@vger.kernel.org
Cc:     Neo Jou <neojou@gmail.com>, Hans Ulli Kroll <linux@ulli-kroll.de>,
        Ping-Ke Shih <pkshih@realtek.com>,
        Yan-Hsuan Chuang <tony0620emma@gmail.com>,
        Kalle Valo <kvalo@kernel.org>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        kernel@pengutronix.de, Johannes Berg <johannes@sipsolutions.net>,
        Alexander Hochbaum <alex@appudo.com>,
        Da Xue <da@libre.computer>, Po-Hao Huang <phhuang@realtek.com>,
        Viktor Petrenko <g0000ga@gmail.com>,
        Sascha Hauer <s.hauer@pengutronix.de>
Subject: [PATCH v3 04/11] rtw88: Drop h2c.lock
Date:   Tue, 22 Nov 2022 15:52:19 +0100
Message-Id: <20221122145226.4065843-5-s.hauer@pengutronix.de>
In-Reply-To: <20221122145226.4065843-1-s.hauer@pengutronix.de>
References: <20221122145226.4065843-1-s.hauer@pengutronix.de>
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The h2c.lock spinlock is used in rtw_fw_send_h2c_command() and
rtw_fw_send_h2c_packet().  Most callers call this with rtwdev->mutex
held, except from one callsite in the debugfs code. The debugfs code
alone doesn't justify the extra lock, so acquire rtwdev->mutex in
debugfs and drop the now unnecessary spinlock.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/net/wireless/realtek/rtw88/debug.c |  2 ++
 drivers/net/wireless/realtek/rtw88/fw.c    | 13 ++++---------
 drivers/net/wireless/realtek/rtw88/main.c  |  1 -
 drivers/net/wireless/realtek/rtw88/main.h  |  2 --
 4 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtw88/debug.c b/drivers/net/wireless/realtek/rtw88/debug.c
index 70e19f2a1a355..f5b8a77ebc67b 100644
--- a/drivers/net/wireless/realtek/rtw88/debug.c
+++ b/drivers/net/wireless/realtek/rtw88/debug.c
@@ -392,7 +392,9 @@ static ssize_t rtw_debugfs_set_h2c(struct file *filp,
 		return -EINVAL;
 	}
 
+	mutex_lock(&rtwdev->mutex);
 	rtw_fw_h2c_cmd_dbg(rtwdev, param);
+	mutex_unlock(&rtwdev->mutex);
 
 	return count;
 }
diff --git a/drivers/net/wireless/realtek/rtw88/fw.c b/drivers/net/wireless/realtek/rtw88/fw.c
index 0b5f903c0f366..a58c80d4825b1 100644
--- a/drivers/net/wireless/realtek/rtw88/fw.c
+++ b/drivers/net/wireless/realtek/rtw88/fw.c
@@ -322,7 +322,7 @@ static void rtw_fw_send_h2c_command(struct rtw_dev *rtwdev,
 		h2c[3], h2c[2], h2c[1], h2c[0],
 		h2c[7], h2c[6], h2c[5], h2c[4]);
 
-	spin_lock(&rtwdev->h2c.lock);
+	lockdep_assert_held(&rtwdev->mutex);
 
 	box = rtwdev->h2c.last_box_num;
 	switch (box) {
@@ -344,7 +344,7 @@ static void rtw_fw_send_h2c_command(struct rtw_dev *rtwdev,
 		break;
 	default:
 		WARN(1, "invalid h2c mail box number\n");
-		goto out;
+		return;
 	}
 
 	ret = read_poll_timeout_atomic(rtw_read8, box_state,
@@ -353,7 +353,7 @@ static void rtw_fw_send_h2c_command(struct rtw_dev *rtwdev,
 
 	if (ret) {
 		rtw_err(rtwdev, "failed to send h2c command\n");
-		goto out;
+		return;
 	}
 
 	for (idx = 0; idx < 4; idx++)
@@ -363,9 +363,6 @@ static void rtw_fw_send_h2c_command(struct rtw_dev *rtwdev,
 
 	if (++rtwdev->h2c.last_box_num >= 4)
 		rtwdev->h2c.last_box_num = 0;
-
-out:
-	spin_unlock(&rtwdev->h2c.lock);
 }
 
 void rtw_fw_h2c_cmd_dbg(struct rtw_dev *rtwdev, u8 *h2c)
@@ -377,15 +374,13 @@ static void rtw_fw_send_h2c_packet(struct rtw_dev *rtwdev, u8 *h2c_pkt)
 {
 	int ret;
 
-	spin_lock(&rtwdev->h2c.lock);
+	lockdep_assert_held(&rtwdev->mutex);
 
 	FW_OFFLOAD_H2C_SET_SEQ_NUM(h2c_pkt, rtwdev->h2c.seq);
 	ret = rtw_hci_write_data_h2c(rtwdev, h2c_pkt, H2C_PKT_SIZE);
 	if (ret)
 		rtw_err(rtwdev, "failed to send h2c packet\n");
 	rtwdev->h2c.seq++;
-
-	spin_unlock(&rtwdev->h2c.lock);
 }
 
 void
diff --git a/drivers/net/wireless/realtek/rtw88/main.c b/drivers/net/wireless/realtek/rtw88/main.c
index 710ddb0283c82..c98e56890401c 100644
--- a/drivers/net/wireless/realtek/rtw88/main.c
+++ b/drivers/net/wireless/realtek/rtw88/main.c
@@ -2067,7 +2067,6 @@ int rtw_core_init(struct rtw_dev *rtwdev)
 	skb_queue_head_init(&rtwdev->coex.queue);
 	skb_queue_head_init(&rtwdev->tx_report.queue);
 
-	spin_lock_init(&rtwdev->h2c.lock);
 	spin_lock_init(&rtwdev->txq_lock);
 	spin_lock_init(&rtwdev->tx_report.q_lock);
 
diff --git a/drivers/net/wireless/realtek/rtw88/main.h b/drivers/net/wireless/realtek/rtw88/main.h
index f24d17f482aaa..4b57542bef1e9 100644
--- a/drivers/net/wireless/realtek/rtw88/main.h
+++ b/drivers/net/wireless/realtek/rtw88/main.h
@@ -2020,8 +2020,6 @@ struct rtw_dev {
 	struct {
 		/* incicate the mail box to use with fw */
 		u8 last_box_num;
-		/* protect to send h2c to fw */
-		spinlock_t lock;
 		u32 seq;
 	} h2c;
 
-- 
2.30.2