From: Johan Hovold Date: Fri, 6 Jan 2017 18:15:23 +0000 (+0100) Subject: USB: serial: ch341: change initial line-control settings X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=7c61b0d5e82bfe29b8dda55745afbf65b6ccc901;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git 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 --- 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)