USB: serial: ftdi_sio: fix FTX sub-integer prescaler

The most-significant bit of the sub-integer-prescaler index is set in
the high byte of the baudrate request wIndex also for FTX devices.

This fixes rates like 1152000 which got mapped to 1.2 MBd.

Reported-by: Vladimir <svv75@mail.ru>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=210351
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
This commit is contained in:
Johan Hovold 2021-01-26 14:59:17 +01:00
parent e2f2dea34c
commit 528222d0c8
1 changed files with 3 additions and 2 deletions

View File

@ -1386,8 +1386,9 @@ static int change_speed(struct tty_struct *tty, struct usb_serial_port *port)
index_value = get_ftdi_divisor(tty, port);
value = (u16)index_value;
index = (u16)(index_value >> 16);
if ((priv->chip_type == FT2232C) || (priv->chip_type == FT2232H) ||
(priv->chip_type == FT4232H) || (priv->chip_type == FT232H)) {
if (priv->chip_type == FT2232C || priv->chip_type == FT2232H ||
priv->chip_type == FT4232H || priv->chip_type == FT232H ||
priv->chip_type == FTX) {
/* Probably the BM type needs the MSB of the encoded fractional
* divider also moved like for the chips above. Any infos? */
index = (u16)((index << 8) | priv->interface);