diff mbox series

[v3,3/4] Bluetooth: hci_qca: Fix frame reassembly errors for wcn3990

Message ID 20181130150247.26294-4-bgodavar@codeaurora.org (mailing list archive)
State Not Applicable, archived
Headers show
Series Bug fixes for Qualcomm BT chip wcn3990 | expand

Commit Message

Balakrishna Godavarthi Nov. 30, 2018, 3:02 p.m. UTC 
During initalization of wcn3990, we observed UART is reading some
stray bytes on the Rx line. This is logging Frame reassembly errors
on the serial console. This could be because of tristate of Tx line
of wcn3990 during boot up.

[  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)

Now we enable a flag during bootup to stop executing proto receive
function and clear it back once the initialization is done.

Signed-off-by: Balakrishna Godavarthi <bgodavar@codeaurora.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>
---
v3:
 * moved ibs disable and qca_flush to different patch
 * updated commnents in code.
v2:
 * Updated commit text & comments.
v1: 
 * initial patch
---
 drivers/bluetooth/hci_qca.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
diff mbox series

Patch

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index 253b5bae30c2..d595a82cb4b9 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 because of BT chip Tx line is in tristate.
+	 * Due to this we read some garbage data on UART Rx.
+	 */
+	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)) {
@@ -1194,6 +1203,7 @@  static int qca_setup(struct hci_uart *hu)
 		if (ret)
 			return ret;
 
+		clear_bit(STATE_DISCARD_RX, &qca->flags);
 		ret = qca_read_soc_version(hdev, &soc_ver);
 		if (ret)
 			return ret;
@@ -1270,6 +1280,12 @@  static const struct qca_vreg_data qca_soc_data = {
 
 static void qca_power_shutdown(struct hci_uart *hu)
 {
+	struct qca_data *qca = hu->priv;
+
+	/* From this point we go into power off state. But serial port is
+	 * still open, discard all the garbage data received on the Rx line.
+	 */
+	set_bit(STATE_DISCARD_RX, &qca->flags);
 	host_set_baudrate(hu, 2400);
 	qca_send_power_pulse(hu, QCA_WCN3990_POWEROFF_PULSE);
 	qca_power_setup(hu, false);