diff options
| author | Johan Hovold <johan@kernel.org> | 2019-04-02 10:19:30 +0200 |
|---|---|---|
| committer | Johan Hovold <johan@kernel.org> | 2019-04-03 09:46:22 +0200 |
| commit | 68270dab97107b5679080b596aa2f5a360f79873 (patch) | |
| tree | d38cfde402e69188afb56f3f771420873f79be33 /drivers/usb | |
| parent | 79a3aaa7b82e3106be97842dedfd8429248896e6 (diff) | |
| download | linux-68270dab97107b5679080b596aa2f5a360f79873.tar.bz2 | |
USB: serial: pl2303: fix non-supported xon/xoff
Older pl2303 devices do not support automatic xon/xoff flow control, so
add add a flag to prevent trying to enable it for legacy device types.
Refactor the IXON test into a helper function to improve readability.
Fixes: 7041d9c3f01b ("USB: serial: pl2303: add support for tx xon/xoff flow control")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/serial/pl2303.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c index bb3f9aa4a909..f1d904706758 100644 --- a/drivers/usb/serial/pl2303.c +++ b/drivers/usb/serial/pl2303.c @@ -156,6 +156,7 @@ enum pl2303_type { struct pl2303_type_data { speed_t max_baud_rate; unsigned long quirks; + unsigned int no_autoxonxoff:1; }; struct pl2303_serial_private { @@ -173,11 +174,12 @@ struct pl2303_private { static const struct pl2303_type_data pl2303_type_data[TYPE_COUNT] = { [TYPE_01] = { - .max_baud_rate = 1228800, - .quirks = PL2303_QUIRK_LEGACY, + .max_baud_rate = 1228800, + .quirks = PL2303_QUIRK_LEGACY, + .no_autoxonxoff = true, }, [TYPE_HX] = { - .max_baud_rate = 12000000, + .max_baud_rate = 12000000, }, }; @@ -552,6 +554,20 @@ static bool pl2303_termios_change(const struct ktermios *a, const struct ktermio return tty_termios_hw_change(a, b) || ixon_change; } +static bool pl2303_enable_xonxoff(struct tty_struct *tty, const struct pl2303_type_data *type) +{ + if (!I_IXON(tty) || I_IXANY(tty)) + return false; + + if (START_CHAR(tty) != 0x11 || STOP_CHAR(tty) != 0x13) + return false; + + if (type->no_autoxonxoff) + return false; + + return true; +} + static void pl2303_set_termios(struct tty_struct *tty, struct usb_serial_port *port, struct ktermios *old_termios) { @@ -681,8 +697,7 @@ static void pl2303_set_termios(struct tty_struct *tty, pl2303_vendor_write(serial, 0x0, 0x41); else pl2303_vendor_write(serial, 0x0, 0x61); - } else if (I_IXON(tty) && !I_IXANY(tty) && START_CHAR(tty) == 0x11 && - STOP_CHAR(tty) == 0x13) { + } else if (pl2303_enable_xonxoff(tty, spriv->type)) { pl2303_vendor_write(serial, 0x0, 0xc0); } else { pl2303_vendor_write(serial, 0x0, 0x0); |