[PATCH v1 4/4] Bluetooth: hci_qca: Fix frame reassembly errors for wcn3990

[Balakrishna Godavarthi]

[  176.929612] Bluetooth: hci_qca.c:qca_recv() hci0: Frame reassembly failed (-84)
[  176.945734] Bluetooth: hci_qca.c:qca_recv() hci0: Frame reassembly failed (-84)
[  176.953298] Bluetooth: hci_qca.c:qca_recv() hci0: Frame reassembly failed (-84)
[  177.010660] Bluetooth: hci_qca.c:qca_recv() hci0: Frame reassembly failed (-84)
[  177.067633] Bluetooth: hci_qca.c:qca_recv() hci0: Frame reassembly failed (-84)

The above errors log on console due to receiving of stray bytes
when wcn3990 boot up's i.e. when during initial setup procedure.

Signed-off-by: Balakrishna Godavarthi <bgodavar@xxxxxxxxxxxxxx>
---
 drivers/bluetooth/hci_qca.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index 97b57e0f4725..341f80606574 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -56,6 +56,7 @@
 
 /* Controller states */
 #define STATE_IN_BAND_SLEEP_ENABLED	1
+#define STATE_DISCARD_RX		2
 
 #define IBS_WAKE_RETRANS_TIMEOUT_MS	100
 #define IBS_TX_IDLE_TIMEOUT_MS		2000
@@ -511,6 +512,7 @@ static int qca_open(struct hci_uart *hu)
 		} else {
 			hu->init_speed = qcadev->init_speed;
 			hu->oper_speed = qcadev->oper_speed;
+			set_bit(STATE_DISCARD_RX, &qca->flags);
 			ret = qca_power_setup(hu, true);
 			if (ret) {
 				destroy_workqueue(qca->workqueue);
@@ -903,6 +905,13 @@ static int qca_recv(struct hci_uart *hu, const void *data, int count)
 	if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
 		return -EUNATCH;
 
+	/* We discard Rx data received while device is in booting
+	 * stage, this is due multiple baudrate switch is causing
+	 * UART to read some garbage data.
+	 */
+	if (test_bit(STATE_DISCARD_RX, &qca->flags))
+		return 0;
+
 	qca->rx_skb = h4_recv_buf(hu->hdev, qca->rx_skb, data, count,
 				  qca_recv_pkts, ARRAY_SIZE(qca_recv_pkts));
 	if (IS_ERR(qca->rx_skb)) {
@@ -1192,10 +1201,12 @@ static int qca_setup(struct hci_uart *hu)
 		set_bit(HCI_QUIRK_USE_BDADDR_PROPERTY, &hdev->quirks);
 		clear_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
 		hu->hdev->shutdown = qca_power_off;
+
 		ret = qca_wcn3990_init(hu);
 		if (ret)
 			return ret;
 
+		clear_bit(STATE_DISCARD_RX, &qca->flags);
 		ret = qca_read_soc_version(hdev, &soc_ver);
 		if (ret)
 			return ret;
@@ -1278,8 +1289,15 @@ static void qca_power_shutdown(struct hci_uart *hu)
 	struct serdev_device *serdev = hu->serdev;
 	unsigned char cmd = QCA_WCN3990_POWEROFF_PULSE;
 
-	host_set_baudrate(hu, 2400);
+	/* From this point we go into power off state,
+	 * disable IBS and discard all the queued data.
+	 */
+	clear_bit(STATE_IN_BAND_SLEEP_ENABLED, &qca->flags);
+	set_bit(STATE_DISCARD_RX, &qca->flags);
+	qca_flush(hu);
+
 	hci_uart_set_flow_control(hu, true);
+	host_set_baudrate(hu, 2400);
 	serdev_device_write(serdev, &cmd, sizeof(cmd), 0);
 	serdev_device_wait_until_sent(serdev, 0);
 	hci_uart_set_flow_control(hu, false);
-- 
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