This is a note to let you know that I've just added the patch titled USB: ftdi_sio: fix chars_in_buffer overhead to the 3.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: usb-ftdi_sio-fix-chars_in_buffer-overhead.patch and it can be found in the queue-3.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a37025b5c702aaf87191cd75fcc42c54454f16f5 Mon Sep 17 00:00:00 2001 From: Johan Hovold <jhovold@xxxxxxxxx> Date: Sun, 5 May 2013 20:32:30 +0200 Subject: USB: ftdi_sio: fix chars_in_buffer overhead From: Johan Hovold <jhovold@xxxxxxxxx> commit a37025b5c702aaf87191cd75fcc42c54454f16f5 upstream. 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 6f602912 ("usb: serial: ftdi_sio: Add missing chars_in_buffer function") without breaking tty_wait_until_sent (used by, for example, tcdrain, tcsendbreak and close). Reported-by: Stas Sergeev <stsp@xxxxxxx> Signed-off-by: Johan Hovold <jhovold@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/serial/ftdi_sio.c | 19 +++++-------------- 1 file changed, 5 insertions(+), 14 deletions(-) --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -931,7 +931,7 @@ static int ftdi_get_icount(struct tty_st static int ftdi_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg); static void ftdi_break_ctl(struct tty_struct *tty, int break_state); -static int ftdi_chars_in_buffer(struct tty_struct *tty); +static bool ftdi_tx_empty(struct usb_serial_port *port); static int ftdi_get_modem_status(struct usb_serial_port *port, unsigned char status[2]); @@ -968,7 +968,7 @@ static struct usb_serial_driver ftdi_sio .ioctl = ftdi_ioctl, .set_termios = ftdi_set_termios, .break_ctl = ftdi_break_ctl, - .chars_in_buffer = ftdi_chars_in_buffer, + .tx_empty = ftdi_tx_empty, }; static struct usb_serial_driver * const serial_drivers[] = { @@ -2092,27 +2092,18 @@ static void ftdi_break_ctl(struct tty_st } -static int ftdi_chars_in_buffer(struct tty_struct *tty) +static bool ftdi_tx_empty(struct usb_serial_port *port) { - struct usb_serial_port *port = tty->driver_data; - int chars; unsigned char buf[2]; int ret; - chars = usb_serial_generic_chars_in_buffer(tty); - if (chars) - goto out; - - /* Check if hardware buffer is empty. */ ret = ftdi_get_modem_status(port, buf); if (ret == 2) { if (!(buf[1] & FTDI_RS_TEMT)) - chars = 1; + return false; } -out: - dev_dbg(&port->dev, "%s - %d\n", __func__, chars); - return chars; + return true; } /* old_termios contains the original termios settings and tty->termios contains Patches currently in stable-queue which might be from jhovold@xxxxxxxxx are queue-3.9/usb-mos7720-fix-dma-to-stack.patch queue-3.9/usb-ti_usb_3410_5052-fix-chars_in_buffer-overhead.patch queue-3.9/usb-ftdi_sio-clean-up-get_modem_status.patch queue-3.9/usb-ftdi_sio-fix-chars_in_buffer-overhead.patch queue-3.9/usb-zte_ev-fix-broken-open.patch queue-3.9/usb-ark3116-fix-control-message-timeout.patch queue-3.9/usb-serial-add-wait_until_sent-operation.patch queue-3.9/usb-io_ti-fix-chars_in_buffer-overhead.patch queue-3.9/usb-mos7840-fix-dma-to-stack.patch queue-3.9/usb-serial-fix-treo-kyocera-interrrupt-in-urb-context.patch queue-3.9/usb-ti_usb_3410_5052-query-hardware-buffer-status-in-chars_in_buffer.patch queue-3.9/usb-serial-add-generic-wait_until_sent-implementation.patch queue-3.9/usb-mos7720-fix-hardware-flow-control.patch queue-3.9/usb-keyspan-fix-bogus-array-index.patch queue-3.9/usb-zte_ev-fix-control-message-timeouts.patch queue-3.9/usb-mos7720-fix-message-timeouts.patch queue-3.9/usb-iuu_phoenix-fix-bulk-message-timeout.patch queue-3.9/usb-whiteheat-fix-broken-port-configuration.patch queue-3.9/usb-ti_usb_3410_5052-remove-lsr-from-port-data.patch queue-3.9/usb-visor-fix-initialisation-of-treo-kyocera-devices.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html