diff options
| author | Johan Hovold <johan@kernel.org> | 2017-01-06 21:15:23 +0300 |
|---|---|---|
| committer | Johan Hovold <johan@kernel.org> | 2017-01-16 14:32:21 +0300 |
| commit | 7c61b0d5e82bfe29b8dda55745afbf65b6ccc901 (patch) | |
| tree | 2a521c0406ef2d8db50555bf77d26755558cf2dd /drivers/usb/serial | |
| parent | 448b6dc5a964c3eca96260138684de10a0e3d9b9 (diff) | |
| download | linux-7c61b0d5e82bfe29b8dda55745afbf65b6ccc901.tar.xz | |
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: Johan Hovold <johan@kernel.org>
Diffstat (limited to 'drivers/usb/serial')
| -rw-r--r-- | drivers/usb/serial/ch341.c | 14 |
1 files 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) |