[PATCH 13/24] USB: serial: ti_usb_3410_5052: fix TIOCGSERIAL implementation

From: Johan Hovold
Date: Wed Apr 07 2021 - 06:40:43 EST


TIOCSSERIAL is a horrid, underspecified, legacy interface which for most
serial devices is only useful for setting the close_delay and
closing_wait parameters.

The port parameter is used to set the I/O port and does not make any
sense to use for USB serial devices.

The xmit_fifo_size parameter could be used to set the hardware transmit
fifo size of a legacy UART when it could not be detected, but the
interface is limited to eight bits and should be left unset when not
used.

The close_delay and closing_wait parameters returned by TIOCGSERIAL are
specified in centiseconds. The driver does not yet support changing
close_delay, but let's report back the default value actually used (0.5
seconds).

Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
drivers/usb/serial/ti_usb_3410_5052.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/serial/ti_usb_3410_5052.c b/drivers/usb/serial/ti_usb_3410_5052.c
index 7252b0ce75a6..4b497c1e850b 100644
--- a/drivers/usb/serial/ti_usb_3410_5052.c
+++ b/drivers/usb/serial/ti_usb_3410_5052.c
@@ -1406,10 +1406,10 @@ static int ti_get_serial_info(struct tty_struct *tty,

ss->type = PORT_16550A;
ss->line = port->minor;
- ss->port = port->port_number;
- ss->xmit_fifo_size = kfifo_size(&port->write_fifo);
ss->baud_base = tport->tp_tdev->td_is_3410 ? 921600 : 460800;
+ ss->close_delay = 50;
ss->closing_wait = cwait;
+
return 0;
}

--
2.26.3