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authorJohan Hovold <johan@kernel.org>2019-04-02 10:19:30 +0200
committerJohan Hovold <johan@kernel.org>2019-04-03 09:46:22 +0200
commit68270dab97107b5679080b596aa2f5a360f79873 (patch)
treed38cfde402e69188afb56f3f771420873f79be33 /drivers/usb/serial
parent79a3aaa7b82e3106be97842dedfd8429248896e6 (diff)
downloadlinux-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/serial')
-rw-r--r--drivers/usb/serial/pl2303.c25
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);