From ff93b19eed0d5c124ee7168650a8e2e120ac8ea4 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Sun, 5 May 2013 20:32:32 +0200 Subject: [PATCH] USB: ti_usb_3410_5052: fix chars_in_buffer overhead 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 2c992cd73 ("USB: ti_usb_3410_5052: query hardware-buffer status in chars_in_buffer") without breaking tty_wait_until_sent (used by, for example, tcdrain, tcsendbreak and close). Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/ti_usb_3410_5052.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff --git a/drivers/usb/serial/ti_usb_3410_5052.c b/drivers/usb/serial/ti_usb_3410_5052.c index cac47ae..c92c5ed 100644 --- a/drivers/usb/serial/ti_usb_3410_5052.c +++ b/drivers/usb/serial/ti_usb_3410_5052.c @@ -101,6 +101,7 @@ static int ti_write(struct tty_struct *tty, struct usb_serial_port *port, const unsigned char *data, int count); static int ti_write_room(struct tty_struct *tty); static int ti_chars_in_buffer(struct tty_struct *tty); +static bool ti_tx_empty(struct usb_serial_port *port); static void ti_throttle(struct tty_struct *tty); static void ti_unthrottle(struct tty_struct *tty); static int ti_ioctl(struct tty_struct *tty, @@ -222,6 +223,7 @@ static struct usb_serial_driver ti_1port_device = { .write = ti_write, .write_room = ti_write_room, .chars_in_buffer = ti_chars_in_buffer, + .tx_empty = ti_tx_empty, .throttle = ti_throttle, .unthrottle = ti_unthrottle, .ioctl = ti_ioctl, @@ -253,6 +255,7 @@ static struct usb_serial_driver ti_2port_device = { .write = ti_write, .write_room = ti_write_room, .chars_in_buffer = ti_chars_in_buffer, + .tx_empty = ti_tx_empty, .throttle = ti_throttle, .unthrottle = ti_unthrottle, .ioctl = ti_ioctl, @@ -684,8 +687,6 @@ static int ti_chars_in_buffer(struct tty_struct *tty) struct ti_port *tport = usb_get_serial_port_data(port); int chars = 0; unsigned long flags; - int ret; - u8 lsr; if (tport == NULL) return 0; @@ -694,16 +695,22 @@ static int ti_chars_in_buffer(struct tty_struct *tty) chars = kfifo_len(&tport->write_fifo); spin_unlock_irqrestore(&tport->tp_lock, flags); - if (!chars) { - ret = ti_get_lsr(tport, &lsr); - if (!ret && !(lsr & TI_LSR_TX_EMPTY)) - chars = 1; - } - dev_dbg(&port->dev, "%s - returns %d\n", __func__, chars); return chars; } +static bool ti_tx_empty(struct usb_serial_port *port) +{ + struct ti_port *tport = usb_get_serial_port_data(port); + int ret; + u8 lsr; + + ret = ti_get_lsr(tport, &lsr); + if (!ret && !(lsr & TI_LSR_TX_EMPTY)) + return false; + + return true; +} static void ti_throttle(struct tty_struct *tty) { -- 2.7.4