From 0ee404ccf1c63aa25363940d474c3c03f8d7e882 Mon Sep 17 00:00:00 2001 From: Uwe Bonnes Date: Fri, 22 Jul 2011 10:41:15 +0200 Subject: usb: serial: ftdi_sio.c: For the FT232H FTDI_SIO_SET_BAUDRATE_REQUEST, index needs to be shifted too the recent addition of the FT232H showed that baudrate was set wrong. See gmane.linux.usb.general: "[ftdi_sio] FT232H support". With the old code, the MSB of the 4 encoded fractional divider bits and more important the clock predivider bits got lost. Adding the FT232H to the code patch were these bits are shifted solves the problem. I verified baud rates with a scope now. I suspect, that the BM device probably needs these bits shifted too. But there is no predivider bit, so this is not obvious, and a missing MSB of the encoded fractional divider only shifts the resulting baudrate minimal. The AM has only 3 bits of encoded fractional divider, so it is not impacted. I have no BM device to test, so I only added a comment and left the code for the BM untouched. Signed-off-by: Uwe Bonnes Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/ftdi_sio.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'drivers/usb') diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index 9afb36143738..7d42f61bd7ad 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -1205,7 +1205,10 @@ static int change_speed(struct tty_struct *tty, struct usb_serial_port *port) urb_index_value = get_ftdi_divisor(tty, port); urb_value = (__u16)urb_index_value; urb_index = (__u16)(urb_index_value >> 16); - if (priv->interface) { /* FT2232C */ + if ((priv->chip_type == FT2232C) || (priv->chip_type == FT2232H) || + (priv->chip_type == FT4232H) || (priv->chip_type == FT232H)) { + /* Probably the BM type needs the MSB of the encoded fractional + * divider also moved like for the chips above. Any infos? */ urb_index = (__u16)((urb_index << 8) | priv->interface); } -- cgit v1.2.3