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 <jo...@kernel.org>
---
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
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