Bluetooth: hci_h5: btrtl: Maintain flow control if wakeup is enabled

For chips that doesn't reset on suspend, we need to provide the correct
value of flow_control when it resumes. Therefore, store the flow
control value when reading from the config file to be reused upon
suspend.
Signed-off-by: Archie Pusaka <apusaka@chromium.org>
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Reviewed-by: Hilda Wu <hildawu@realtek.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/hci_h5.c

@@ -54,6 +54,7 @@ enum {
 	H5_RX_ESC,		/* SLIP escape mode */
 	H5_TX_ACK_REQ,		/* Pending ack to send */
 	H5_WAKEUP_DISABLE,	/* Device cannot wake host */
+	H5_HW_FLOW_CONTROL,	/* Use HW flow control */
 };
 
 struct h5 {
@@ -920,6 +921,9 @@ static int h5_btrtl_setup(struct h5 *h5)
 	serdev_device_set_baudrate(h5->hu->serdev, controller_baudrate);
 	serdev_device_set_flow_control(h5->hu->serdev, flow_control);
 
+	if (flow_control)
+		set_bit(H5_HW_FLOW_CONTROL, &h5->flags);
+
 	err = btrtl_download_firmware(h5->hu->hdev, btrtl_dev);
 	/* Give the device some time before the hci-core sends it a reset */
 	usleep_range(10000, 20000);
@@ -1012,7 +1016,11 @@ static int h5_btrtl_resume(struct h5 *h5)
 		queue_work(system_long_wq, &reprobe->work);
 	} else {
 		gpiod_set_value_cansleep(h5->device_wake_gpio, 1);
+
+		if (test_bit(H5_HW_FLOW_CONTROL, &h5->flags))
+			serdev_device_set_flow_control(h5->hu->serdev, true);
 	}
+
 	return 0;
 }