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Commit 7c61b0d5 authored by Johan Hovold's avatar Johan Hovold
Browse files

USB: serial: ch341: change initial line-control settings 



Some CH340 devices appear unable to change the initial LCR settings, so
set a sane 8N1 default during probe to enable basic support for such
devices.

Also drop a redundant LCR read during device initialisation.

Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
parent 448b6dc5

drivers/usb/serial/ch341.c

+5 −9
Original line number Diff line number Diff line
@@ -238,15 +238,6 @@ static int ch341_configure(struct usb_device *dev, struct ch341_private *priv) 
	if (r < 0)

		goto out;



	/* expect two bytes 0x56 0x00 */

	r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x2518, 0, buffer, size);

	if (r < 0)

		goto out;



	r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x2518, 0x0050);

	if (r < 0)

		goto out;



	r = ch341_set_baudrate_lcr(dev, priv, priv->lcr);

	if (r < 0)

		goto out;
@@ -268,6 +259,11 @@ static int ch341_port_probe(struct usb_serial_port *port) 


	spin_lock_init(&priv->lock);

	priv->baud_rate = DEFAULT_BAUD_RATE;

	/*

	 * Some CH340 devices appear unable to change the initial LCR

	 * settings, so set a sane 8N1 default.

	 */

	priv->lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX | CH341_LCR_CS8;



	r = ch341_configure(port->serial->dev, priv);

	if (r < 0)