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authorJohan Hovold <jhovold@gmail.com>2013-05-05 22:32:32 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-05-17 04:32:22 +0400
commitff93b19eed0d5c124ee7168650a8e2e120ac8ea4 (patch)
tree57151bdd9f8a28509f2feac7ac3755833395c1e5 /drivers/usb/serial/ti_usb_3410_5052.c
parentb16634adce951a7371be931487034f7365971ed0 (diff)
downloadlinux-ff93b19eed0d5c124ee7168650a8e2e120ac8ea4.tar.xz
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 <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/serial/ti_usb_3410_5052.c')
-rw-r--r--drivers/usb/serial/ti_usb_3410_5052.c23
1 files 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 cac47aef2918..c92c5ed4e580 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)
{