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From:   Harish Bandi <c-hbandi@codeaurora.org>
To:     marcel@holtmann.org, johan.hedberg@gmail.com
Cc:     mka@chromium.org, linux-kernel@vger.kernel.org,
        linux-bluetooth@vger.kernel.org, hemantg@codeaurora.org,
        linux-arm-msm@vger.kernel.org, bgodavar@codeaurora.org,
        anubhavg@codeaurora.org, Harish Bandi <c-hbandi@codeaurora.org>
Subject: [PATCH v1] bluetooth: hci_qca: disable irqs when spinlock is acquired
Date:   Wed,  4 Sep 2019 10:04:16 +0530
Message-Id: <1567571656-32403-1-git-send-email-c-hbandi@codeaurora.org>
Sender: linux-bluetooth-owner@vger.kernel.org
Precedence: bulk

Looks like Deadlock is observed in hci_qca while performing
stress and stability tests. Since same lock is getting
acquired from qca_wq_awake_rx and hci_ibs_tx_idle_timeout
seeing spinlock recursion, irqs should be disable while
acquiring the spinlock always.

Signed-off-by: Harish Bandi <c-hbandi@codeaurora.org>
---
 drivers/bluetooth/hci_qca.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index d33828f..e3164c2 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -309,13 +309,14 @@ static void qca_wq_awake_device(struct work_struct *work)
 					    ws_awake_device);
 	struct hci_uart *hu = qca->hu;
 	unsigned long retrans_delay;
+	unsigned long flags;
 
 	BT_DBG("hu %p wq awake device", hu);
 
 	/* Vote for serial clock */
 	serial_clock_vote(HCI_IBS_TX_VOTE_CLOCK_ON, hu);
 
-	spin_lock(&qca->hci_ibs_lock);
+	spin_lock_irqsave(&qca->hci_ibs_lock, flags);
 
 	/* Send wake indication to device */
 	if (send_hci_ibs_cmd(HCI_IBS_WAKE_IND, hu) < 0)
@@ -327,7 +328,7 @@ static void qca_wq_awake_device(struct work_struct *work)
 	retrans_delay = msecs_to_jiffies(qca->wake_retrans);
 	mod_timer(&qca->wake_retrans_timer, jiffies + retrans_delay);
 
-	spin_unlock(&qca->hci_ibs_lock);
+	spin_unlock_irqrestore(&qca->hci_ibs_lock, flags);
 
 	/* Actually send the packets */
 	hci_uart_tx_wakeup(hu);
@@ -338,12 +339,13 @@ static void qca_wq_awake_rx(struct work_struct *work)
 	struct qca_data *qca = container_of(work, struct qca_data,
 					    ws_awake_rx);
 	struct hci_uart *hu = qca->hu;
+	unsigned long flags;
 
 	BT_DBG("hu %p wq awake rx", hu);
 
 	serial_clock_vote(HCI_IBS_RX_VOTE_CLOCK_ON, hu);
 
-	spin_lock(&qca->hci_ibs_lock);
+	spin_lock_irqsave(&qca->hci_ibs_lock, flags);
 	qca->rx_ibs_state = HCI_IBS_RX_AWAKE;
 
 	/* Always acknowledge device wake up,
@@ -354,7 +356,7 @@ static void qca_wq_awake_rx(struct work_struct *work)
 
 	qca->ibs_sent_wacks++;
 
-	spin_unlock(&qca->hci_ibs_lock);
+	spin_unlock_irqrestore(&qca->hci_ibs_lock, flags);
 
 	/* Actually send the packets */
 	hci_uart_tx_wakeup(hu);
-- 
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