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: Johan Hovold <johan@xxxxxxxxxx> --- drivers/usb/serial/ch341.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c index c51ec9802856..351745aec0e1 100644 --- a/drivers/usb/serial/ch341.c +++ b/drivers/usb/serial/ch341.c @@ -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) -- 2.10.2 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
