Commit d54fdcf9 authored Dec 02, 2017 by David Lechner Committed by Marcel Holtmann Dec 13, 2017

Bluetooth: serdev: hci_ll: Wait for CTS instead of using msleep



When a TI Bluetooth chip is reset, it takes about 100ms for the RTS line of
the chip to deassert. For my use case with a TI CC2560A chip, this delay
was not long enough and caused the local UART to never transmit at all (TI
AM1808 SoC UART2).

We can wait for the CTS signal using serdev_device_wait_for_cts() instead
of trying to guess using msleep().

Also changed the comment to be more informative while we are touching this
code.

Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

parent 059fb823

drivers/bluetooth/hci_ll.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -674,11 +674,15 @@ static int ll_setup(struct hci_uart *hu)
		serdev_device_set_flow_control(serdev, true);

		do {
		/* Configure BT_EN to HIGH state */
		/* Reset the Bluetooth device */
		gpiod_set_value_cansleep(lldev->enable_gpio, 0);
		msleep(5);
		gpiod_set_value_cansleep(lldev->enable_gpio, 1);
		msleep(100);
		err = serdev_device_wait_for_cts(serdev, true, 200);
		if (err) {
		bt_dev_err(hu->hdev, "Failed to get CTS");
		return err;
		}

		err = download_firmware(lldev);
		if (!err)