[PATCH v1 1/4] Bluetooth: hci_qca: use wait_until_sent() for power pulses

[Balakrishna Godavarthi]

wcn3990 requires a power pulse to turn ON/OFF along with
regulators. Sometimes we are observing the power pulses are sent
out with some time delay, due to queuing these commands. This is
causing synchronization issues with chip, which intern delay the
chip setup or may end up with communication issues.

Signed-off-by: Balakrishna Godavarthi <bgodavar@xxxxxxxxxxxxxx>
---
 drivers/bluetooth/hci_qca.c | 22 +++++++++-------------
 1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index f72ded4ec9ae..051f081d1835 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -1016,8 +1016,7 @@ static inline void host_set_baudrate(struct hci_uart *hu, unsigned int speed)
 static int qca_send_power_pulse(struct hci_dev *hdev, u8 cmd)
 {
 	struct hci_uart *hu = hci_get_drvdata(hdev);
-	struct qca_data *qca = hu->priv;
-	struct sk_buff *skb;
+	int ret;
 
 	/* These power pulses are single byte command which are sent
 	 * at required baudrate to wcn3990. On wcn3990, we have an external
@@ -1030,18 +1029,14 @@ static int qca_send_power_pulse(struct hci_dev *hdev, u8 cmd)
 	 * sending power pulses to SoC.
 	 */
 	bt_dev_dbg(hdev, "sending power pulse %02x to SoC", cmd);
-
-	skb = bt_skb_alloc(sizeof(cmd), GFP_KERNEL);
-	if (!skb)
-		return -ENOMEM;
-
 	hci_uart_set_flow_control(hu, true);
+	ret = serdev_device_write(hu->serdev, &cmd, sizeof(cmd), 0);
+	if (ret < 0) {
+		bt_dev_err(hdev, "failed to send power pulse %02x to SoC", cmd);
+		return ret;
+	}
 
-	skb_put_u8(skb, cmd);
-	hci_skb_pkt_type(skb) = HCI_COMMAND_PKT;
-
-	skb_queue_tail(&qca->txq, skb);
-	hci_uart_tx_wakeup(hu);
+	serdev_device_wait_until_sent(hu->serdev, 0);
 
 	/* Wait for 100 uS for SoC to settle down */
 	usleep_range(100, 200);
@@ -1283,7 +1278,8 @@ static void qca_power_shutdown(struct hci_uart *hu)
 
 	host_set_baudrate(hu, 2400);
 	hci_uart_set_flow_control(hu, true);
-	serdev_device_write_buf(serdev, &cmd, sizeof(cmd));
+	serdev_device_write(serdev, &cmd, sizeof(cmd), 0);
+	serdev_device_wait_until_sent(serdev, 0);
 	hci_uart_set_flow_control(hu, false);
 	qca_power_setup(hu, false);
 }
-- 
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