Received-SPF: pass (google.com: domain of linux-wireless+bounces-898-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
From: Baochen Qiang <quic_bqiang@quicinc.com>
To: <ath11k@lists.infradead.org>
CC: <linux-wireless@vger.kernel.org>
Subject: [PATCH v10 03/12] wifi: ath11k: fix a possible dead lock caused by ab->base_lock
Date: Mon, 18 Dec 2023 16:58:35 +0800
Message-ID: <20231218085844.2658-4-quic_bqiang@quicinc.com>
In-Reply-To: <20231218085844.2658-1-quic_bqiang@quicinc.com>
References: <20231218085844.2658-1-quic_bqiang@quicinc.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Content-Type: text/plain

spin_lock/spin_unlock are used in ath11k_reg_chan_list_event to
acquire/release ab->base_lock. For now this is safe because that
function is only called in soft IRQ context.

But ath11k_reg_chan_list_event() will be called from process
context in an upcoming patch, and this can result in a deadlock if
ab->base_lock is acquired in process context and then soft IRQ occurs
on the same CPU and tries to acquire that lock.

Fix it by using spin_lock_bh and spin_unlock_bh instead.

Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.23

Fixes: 69a0fcf8a9f2 ("ath11k: Avoid reg rules update during firmware recovery")
Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
Signed-off-by: Wen Gong <quic_wgong@quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
---
v10:
 no change.
v9:
 no change.
v8:
 no change.
v7:
 no change.

 drivers/net/wireless/ath/ath11k/wmi.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/wmi.c b/drivers/net/wireless/ath/ath11k/wmi.c
index a48aafc79b90..9f8a62c334b0 100644
--- a/drivers/net/wireless/ath/ath11k/wmi.c
+++ b/drivers/net/wireless/ath/ath11k/wmi.c
@@ -7142,13 +7142,13 @@ int ath11k_reg_handle_chan_list(struct ath11k_base *ab,
 	/* Avoid default reg rule updates sent during FW recovery if
 	 * it is already available
 	 */
-	spin_lock(&ab->base_lock);
+	spin_lock_bh(&ab->base_lock);
 	if (test_bit(ATH11K_FLAG_RECOVERY, &ab->dev_flags) &&
 	    ab->default_regd[pdev_idx]) {
-		spin_unlock(&ab->base_lock);
+		spin_unlock_bh(&ab->base_lock);
 		goto retfail;
 	}
-	spin_unlock(&ab->base_lock);
+	spin_unlock_bh(&ab->base_lock);
 
 	if (pdev_idx >= ab->num_radios) {
 		/* Process the event for phy0 only if single_pdev_only
@@ -7201,7 +7201,7 @@ int ath11k_reg_handle_chan_list(struct ath11k_base *ab,
 		ab->reg_info_store[pdev_idx] = *reg_info;
 	}
 
-	spin_lock(&ab->base_lock);
+	spin_lock_bh(&ab->base_lock);
 	if (ab->default_regd[pdev_idx]) {
 		/* The initial rules from FW after WMI Init is to build
 		 * the default regd. From then on, any rules updated for
@@ -7221,7 +7221,7 @@ int ath11k_reg_handle_chan_list(struct ath11k_base *ab,
 		ab->default_regd[pdev_idx] = regd;
 	}
 	ab->dfs_region = reg_info->dfs_region;
-	spin_unlock(&ab->base_lock);
+	spin_unlock_bh(&ab->base_lock);
 
 	return 0;
 
-- 
2.25.1