Commit 4cd1de0a authored by Alan Cox's avatar Alan Cox Committed by Linus Torvalds
Browse files

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: default avatarAlan Cox <alan@linux.intel.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d6be791c

drivers/usb/serial/generic.c

+11 −4
Original line number Diff line number Diff line
@@ -424,11 +424,18 @@ static void flush_and_resubmit_read_urb(struct usb_serial_port *port) 
	if (!tty)

		goto done;



	/* 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);

done: