diff options
| author | Johan Hovold <jhovold@gmail.com> | 2013-05-05 20:32:30 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-06-13 10:49:49 -0700 |
| commit | 487bc65d5a0bba6dbc8f07c46734c90b500e4b64 (patch) | |
| tree | a7e4adc3bed0ffad856ecd8a48bea562510c525f | |
| parent | 2ee6eba44c93469e890498c46a1fb6a3b8ccfcc4 (diff) | |
USB: ftdi_sio: fix chars_in_buffer overhead
commit a37025b5c702aaf87191cd75fcc42c54454f16f5 upstream.
Use the new generic usb-serial wait_until_sent implementation to wait
for hardware buffers to drain.
This removes the need to check the hardware buffers in chars_in_buffer
and thus removes the overhead introduced by commit 6f602912 ("usb:
serial: ftdi_sio: Add missing chars_in_buffer function") without
breaking tty_wait_until_sent (used by, for example, tcdrain, tcsendbreak
and close).
Reported-by: Stas Sergeev <stsp@list.ru>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/serial/ftdi_sio.c | 19 |
1 files changed, 5 insertions, 14 deletions
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index 653c053a5fb1..e8e28379c8b6 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -931,7 +931,7 @@ static int ftdi_get_icount(struct tty_struct *tty, static int ftdi_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg); static void ftdi_break_ctl(struct tty_struct *tty, int break_state); -static int ftdi_chars_in_buffer(struct tty_struct *tty); +static bool ftdi_tx_empty(struct usb_serial_port *port); static int ftdi_get_modem_status(struct usb_serial_port *port, unsigned char status[2]); @@ -968,7 +968,7 @@ static struct usb_serial_driver ftdi_sio_device = { .ioctl = ftdi_ioctl, .set_termios = ftdi_set_termios, .break_ctl = ftdi_break_ctl, - .chars_in_buffer = ftdi_chars_in_buffer, + .tx_empty = ftdi_tx_empty, }; static struct usb_serial_driver * const serial_drivers[] = { @@ -2092,27 +2092,18 @@ static void ftdi_break_ctl(struct tty_struct *tty, int break_state) } -static int ftdi_chars_in_buffer(struct tty_struct *tty) +static bool ftdi_tx_empty(struct usb_serial_port *port) { - struct usb_serial_port *port = tty->driver_data; - int chars; unsigned char buf[2]; int ret; - chars = usb_serial_generic_chars_in_buffer(tty); - if (chars) - goto out; - - /* Check if hardware buffer is empty. */ ret = ftdi_get_modem_status(port, buf); if (ret == 2) { if (!(buf[1] & FTDI_RS_TEMT)) - chars = 1; + return false; } -out: - dev_dbg(&port->dev, "%s - %d\n", __func__, chars); - return chars; + return true; } /* old_termios contains the original termios settings and tty->termios contains |