Bluetooth: hci_qca: Retry btsoc initialize when it fails

This patch adds the retry of btsoc initialization when it fails. There are
reports that the btsoc initialization may fail on some platforms but the
repro ratio is very low. The symptoms is the firmware downloading failed
due to the UART write timed out. The failure may be caused by UART,
platform HW or the btsoc itself but it's very difficlut to root cause,
given the repro ratio is very low. Add a retry for the btsoc initialization
can work around most of the failures and make Bluetooth finally works.
Signed-off-by: Rocky Liao <rjliao@codeaurora.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/hci_qca.c

@@ -55,6 +55,9 @@
 /* Controller debug log header */
 #define QCA_DEBUG_HANDLE	0x2EDC
 
+/* max retry count when init fails */
+#define MAX_INIT_RETRIES 3
+
 /* Controller dump header */
 #define QCA_SSR_DUMP_HANDLE		0x0108
 #define QCA_DUMP_PACKET_SIZE		255
@@ -1539,6 +1542,7 @@ static int qca_setup(struct hci_uart *hu)
 	struct hci_dev *hdev = hu->hdev;
 	struct qca_data *qca = hu->priv;
 	unsigned int speed, qca_baudrate = QCA_BAUDRATE_115200;
+	unsigned int retries = 0;
 	enum qca_btsoc_type soc_type = qca_soc_type(hu);
 	const char *firmware_name = qca_get_firmware_name(hu);
 	int ret;
@@ -1559,6 +1563,7 @@ static int qca_setup(struct hci_uart *hu)
 	bt_dev_info(hdev, "setting up %s",
 		qca_is_wcn399x(soc_type) ? "wcn399x" : "ROME");
 
+retry:
 	ret = qca_power_on(hdev);
 	if (ret)
 		return ret;
@@ -1613,6 +1618,20 @@ static int qca_setup(struct hci_uart *hu)
 		 * patch/nvm-config is found, so run with original fw/config.
 		 */
 		ret = 0;
+	} else {
+		if (retries < MAX_INIT_RETRIES) {
+			qca_power_shutdown(hu);
+			if (hu->serdev) {
+				serdev_device_close(hu->serdev);
+				ret = serdev_device_open(hu->serdev);
+				if (ret) {
+					bt_dev_err(hdev, "failed to open port");
+					return ret;
+				}
+			}
+			retries++;
+			goto retry;
+		}
 	}
 
 	/* Setup bdaddr */