[PATCH v1 1/2] Bluetooth: btnxpuart: Correct the Independent Reset handling after FW dump

[Neeraj Sanjay Kale]

This adds proper handling for the independent reset command sent by the
driver after FW dump is complete.

In normal scenario, the independent reset vendor command gives a success
response before jumping to bootcode.

However, when FW goes in a bad state, and sends out FW dump packets, the
independent reset command does not get any response from the controller.

[  159.807732] Bluetooth: hci0: ==== Start FW dump ===
[  180.759060] Bluetooth: hci0: ==== FW dump complete ===
[  182.779208] Bluetooth: hci0: command 0xfcfc tx timeout
[  183.364974] Bluetooth: hci0: ChipID: 7601, Version: 0
[  183.368490] Bluetooth: hci0: Request Firmware: nxp/uartspi_n61x_v1.bin.se
[  184.679977] Bluetooth: hci0: FW Download Complete: 417064 bytes
[  187.963102] Bluetooth: hci0: Opcode 0x0c03 failed: -110

As a fix for such scenario, the independent reset vendor command is sent
using the __hci_cmd_send() API, which does not expect any response for
vendor commands.

__hci_cmd_send is non blocking, so before the tx_work is scheduled, it
sometimes gets canceled and 3F|FC command is never sent. Adding a small
delay after __hci_cmd_send allows the command to be sent to the
controller.

Signed-off-by: Neeraj Sanjay Kale <neeraj.sanjaykale@xxxxxxx>
Tested-by: Jean-Yves Salaün <jean-yves.salaun@xxxxxxx>
---
 drivers/bluetooth/btnxpuart.c | 32 +++++++++++++++++++++++---------
 1 file changed, 23 insertions(+), 9 deletions(-)

diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c
index c56b52bd8d98..f40794be2d89 100644
--- a/drivers/bluetooth/btnxpuart.c
+++ b/drivers/bluetooth/btnxpuart.c
@@ -367,17 +367,26 @@ static u8 crc8_table[CRC8_TABLE_SIZE];
 
 static struct sk_buff *nxp_drv_send_cmd(struct hci_dev *hdev, u16 opcode,
 					u32 plen,
-					void *param)
+					void *param,
+					bool resp)
 {
 	struct btnxpuart_dev *nxpdev = hci_get_drvdata(hdev);
 	struct ps_data *psdata = &nxpdev->psdata;
-	struct sk_buff *skb;
+	struct sk_buff *skb = NULL;
 
 	/* set flag to prevent nxp_enqueue from parsing values from this command and
 	 * calling hci_cmd_sync_queue() again.
 	 */
 	psdata->driver_sent_cmd = true;
-	skb = __hci_cmd_sync(hdev, opcode, plen, param, HCI_CMD_TIMEOUT);
+	if (resp) {
+		skb = __hci_cmd_sync(hdev, opcode, plen, param, HCI_CMD_TIMEOUT);
+	} else {
+		__hci_cmd_send(hdev, opcode, plen, param);
+		/* Allow command to be sent before tx_work is cancelled
+		 * by btnxpuart_flush()
+		 */
+		msleep(20);
+	}
 	psdata->driver_sent_cmd = false;
 
 	return skb;
@@ -597,7 +606,7 @@ static int send_ps_cmd(struct hci_dev *hdev, void *data)
 		pcmd.ps_cmd = BT_PS_DISABLE;
 	pcmd.c2h_ps_interval = __cpu_to_le16(psdata->c2h_ps_interval);
 
-	skb = nxp_drv_send_cmd(hdev, HCI_NXP_AUTO_SLEEP_MODE, sizeof(pcmd), &pcmd);
+	skb = nxp_drv_send_cmd(hdev, HCI_NXP_AUTO_SLEEP_MODE, sizeof(pcmd), &pcmd, true);
 	if (IS_ERR(skb)) {
 		bt_dev_err(hdev, "Setting Power Save mode failed (%ld)", PTR_ERR(skb));
 		return PTR_ERR(skb);
@@ -646,7 +655,7 @@ static int send_wakeup_method_cmd(struct hci_dev *hdev, void *data)
 		break;
 	}
 
-	skb = nxp_drv_send_cmd(hdev, HCI_NXP_WAKEUP_METHOD, sizeof(pcmd), &pcmd);
+	skb = nxp_drv_send_cmd(hdev, HCI_NXP_WAKEUP_METHOD, sizeof(pcmd), &pcmd, true);
 	if (IS_ERR(skb)) {
 		bt_dev_err(hdev, "Setting wake-up method failed (%ld)", PTR_ERR(skb));
 		return PTR_ERR(skb);
@@ -1272,7 +1281,7 @@ static int nxp_set_baudrate_cmd(struct hci_dev *hdev, void *data)
 	if (!psdata)
 		return 0;
 
-	skb = nxp_drv_send_cmd(hdev, HCI_NXP_SET_OPER_SPEED, 4, (u8 *)&new_baudrate);
+	skb = nxp_drv_send_cmd(hdev, HCI_NXP_SET_OPER_SPEED, 4, (u8 *)&new_baudrate, true);
 	if (IS_ERR(skb)) {
 		bt_dev_err(hdev, "Setting baudrate failed (%ld)", PTR_ERR(skb));
 		return PTR_ERR(skb);
@@ -1330,7 +1339,7 @@ static void nxp_coredump(struct hci_dev *hdev)
 	struct sk_buff *skb;
 	u8 pcmd = 2;
 
-	skb = nxp_drv_send_cmd(hdev, HCI_NXP_TRIGGER_DUMP, 1, &pcmd);
+	skb = nxp_drv_send_cmd(hdev, HCI_NXP_TRIGGER_DUMP, 1, &pcmd, true);
 	if (IS_ERR(skb))
 		bt_dev_err(hdev, "Failed to trigger FW Dump. (%ld)", PTR_ERR(skb));
 	else
@@ -1372,7 +1381,6 @@ static int nxp_process_fw_dump(struct hci_dev *hdev, struct sk_buff *skb)
 
 	if (buf_len == 0) {
 		bt_dev_warn(hdev, "==== FW dump complete ===");
-		clear_bit(BTNXPUART_FW_DUMP_IN_PROGRESS, &nxpdev->tx_state);
 		hci_devcd_complete(hdev);
 		nxp_set_ind_reset(hdev, NULL);
 	}
@@ -1486,7 +1494,13 @@ static int nxp_shutdown(struct hci_dev *hdev)
 	u8 pcmd = 0;
 
 	if (ind_reset_in_progress(nxpdev)) {
-		skb = nxp_drv_send_cmd(hdev, HCI_NXP_IND_RESET, 1, &pcmd);
+		if (test_and_clear_bit(BTNXPUART_FW_DUMP_IN_PROGRESS,
+				       &nxpdev->tx_state))
+			skb = nxp_drv_send_cmd(hdev, HCI_NXP_IND_RESET, 1,
+					       &pcmd, false);
+		else
+			skb = nxp_drv_send_cmd(hdev, HCI_NXP_IND_RESET, 1,
+					       &pcmd, true);
 		serdev_device_set_flow_control(nxpdev->serdev, false);
 		set_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
 		/* HCI_NXP_IND_RESET command may not returns any response */
-- 
2.34.1