tty: Sort out the USB sysrq changes that wrecked performance

We can't go around calling all sorts of magic per character functions at
full rate 3G data speed.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alan Cox 2009-07-09 13:35:52 +01:00 committed by Linus Torvalds
parent d6be791cbd
commit 4cd1de0afa
1 changed files with 11 additions and 4 deletions

View File

@ -424,10 +424,17 @@ static void flush_and_resubmit_read_urb(struct usb_serial_port *port)
if (!tty)
goto done;
/* Push data to tty */
for (i = 0; i < urb->actual_length; i++, ch++) {
if (!usb_serial_handle_sysrq_char(port, *ch))
tty_insert_flip_char(tty, *ch, TTY_NORMAL);
/* The per character mucking around with sysrq path it too slow for
stuff like 3G modems, so shortcircuit it in the 99.9999999% of cases
where the USB serial is not a console anyway */
if (!port->console || !port->sysrq)
tty_insert_flip_string(tty, ch, urb->actual_length);
else {
/* Push data to tty */
for (i = 0; i < urb->actual_length; i++, ch++) {
if (!usb_serial_handle_sysrq_char(port, *ch))
tty_insert_flip_char(tty, *ch, TTY_NORMAL);
}
}
tty_flip_buffer_push(tty);
tty_kref_put(tty);