linux-kernel - [PATCH 2/3] Bluetooth: hci_qca: Skip serdev wait when no transfer is pending

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Date:   Fri,  5 Jun 2020 11:46:10 -0700
From:   Matthias Kaehlcke <mka@...omium.org>
To:     Marcel Holtmann <marcel@...tmann.org>,
        Johan Hedberg <johan.hedberg@...il.com>
Cc:     linux-bluetooth@...r.kernel.org,
        Rocky Liao <rjliao@...eaurora.org>,
        Zijun Hu <zijuhu@...eaurora.org>, linux-kernel@...r.kernel.org,
        Balakrishna Godavarthi <bgodavar@...eaurora.org>,
        Abhishek Pandit-Subedi <abhishekpandit@...omium.org>,
        Claire Chang <tientzu@...omium.org>,
        Matthias Kaehlcke <mka@...omium.org>
Subject: [PATCH 2/3] Bluetooth: hci_qca: Skip serdev wait when no transfer is pending

qca_suspend() calls serdev_device_wait_until_sent() regardless of
whether a transfer is pending. While it does no active harm since
the function should return immediately it makes the code more
confusing. Add a flag to track whether a transfer is pending and
only call serdev_device_wait_until_sent() is needed.

Signed-off-by: Matthias Kaehlcke <mka@...omium.org>
---

 drivers/bluetooth/hci_qca.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index b1d82d32892e9..90ffd8ca1fb0d 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -2050,6 +2050,7 @@ static int __maybe_unused qca_suspend(struct device *dev)
 	struct hci_uart *hu = &qcadev->serdev_hu;
 	struct qca_data *qca = hu->priv;
 	unsigned long flags;
+	bool tx_pending = false;
 	int ret = 0;
 	u8 cmd;
 
@@ -2083,6 +2084,7 @@ static int __maybe_unused qca_suspend(struct device *dev)
 
 		qca->tx_ibs_state = HCI_IBS_TX_ASLEEP;
 		qca->ibs_sent_slps++;
+		tx_pending = true;
 		break;
 
 	case HCI_IBS_TX_ASLEEP:
@@ -2099,8 +2101,10 @@ static int __maybe_unused qca_suspend(struct device *dev)
 	if (ret < 0)
 		goto error;
 
-	serdev_device_wait_until_sent(hu->serdev,
-				      msecs_to_jiffies(CMD_TRANS_TIMEOUT_MS));
+	if (tx_pending) {
+		serdev_device_wait_until_sent(hu->serdev,
+					      msecs_to_jiffies(CMD_TRANS_TIMEOUT_MS));
+	}
 
 	/* Wait for HCI_IBS_SLEEP_IND sent by device to indicate its Tx is going
 	 * to sleep, so that the packet does not wake the system later.
-- 
2.27.0.278.ge193c7cf3a9-goog