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authorJohan Hovold <jhovold@gmail.com>2013-05-05 20:32:31 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-05-17 02:32:22 +0200
commitb16634adce951a7371be931487034f7365971ed0 (patch)
tree8d7242002e36c347c5d2a4ce7154aacfeca73633 /drivers/usb/serial/io_ti.c
parentUSB: ftdi_sio: fix chars_in_buffer overhead (diff)
downloadlinux-b16634adce951a7371be931487034f7365971ed0.tar.xz
linux-b16634adce951a7371be931487034f7365971ed0.zip
USB: io_ti: 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 263e1f9f ("USB: io_ti: 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/io_ti.c')
-rw-r--r--drivers/usb/serial/io_ti.c22
1 files changed, 14 insertions, 8 deletions
diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c
index 158bf4bc29cc..1be6ba7bee27 100644
--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -2019,8 +2019,6 @@ static int edge_chars_in_buffer(struct tty_struct *tty)
struct edgeport_port *edge_port = usb_get_serial_port_data(port);
int chars = 0;
unsigned long flags;
- int ret;
-
if (edge_port == NULL)
return 0;
@@ -2028,16 +2026,22 @@ static int edge_chars_in_buffer(struct tty_struct *tty)
chars = kfifo_len(&edge_port->write_fifo);
spin_unlock_irqrestore(&edge_port->ep_lock, flags);
- if (!chars) {
- ret = tx_active(edge_port);
- if (ret > 0)
- chars = ret;
- }
-
dev_dbg(&port->dev, "%s - returns %d\n", __func__, chars);
return chars;
}
+static bool edge_tx_empty(struct usb_serial_port *port)
+{
+ struct edgeport_port *edge_port = usb_get_serial_port_data(port);
+ int ret;
+
+ ret = tx_active(edge_port);
+ if (ret > 0)
+ return false;
+
+ return true;
+}
+
static void edge_throttle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
@@ -2557,6 +2561,7 @@ static struct usb_serial_driver edgeport_1port_device = {
.write = edge_write,
.write_room = edge_write_room,
.chars_in_buffer = edge_chars_in_buffer,
+ .tx_empty = edge_tx_empty,
.break_ctl = edge_break,
.read_int_callback = edge_interrupt_callback,
.read_bulk_callback = edge_bulk_in_callback,
@@ -2589,6 +2594,7 @@ static struct usb_serial_driver edgeport_2port_device = {
.write = edge_write,
.write_room = edge_write_room,
.chars_in_buffer = edge_chars_in_buffer,
+ .tx_empty = edge_tx_empty,
.break_ctl = edge_break,
.read_int_callback = edge_interrupt_callback,
.read_bulk_callback = edge_bulk_in_callback,