Merge branch 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6

* 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6:
  n_gsm: Fix length handling
  n_gsm: Copy n2 over when configuring via ioctl interface
  serial: bfin_5xx: grab port lock before making port termios changes
  serial: bfin_5xx: disable CON_PRINTBUFFER for consoles
  serial: bfin_5xx: remove redundant SSYNC to improve TX speed
  serial: bfin_5xx: always include DMA headers
  vcs: make proper usage of the poll flags
  amiserial: Remove unused variable icount
  8250: Fix tcsetattr to avoid ioctl(TIOCMIWAIT) hang
  tty_ldisc: Fix BUG() on hangup
  TTY: restore tty_ldisc_wait_idle
  SERIAL: blacklist si3052 chip
  drivers/serial/bfin_5xx.c: Fix line continuation defects
  tty: prevent DOS in the flush_to_ldisc
  8250: add support for Kouwell KW-L221N-2
  nozomi: Fix warning from the previous TIOCGCOUNT changes
  tty: fix warning in synclink driver
  tty: Fix formatting in tty.h
  tty: the development tree is now done in git

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 4d8e14b7aa93..dd5e1ac22251 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -2343,8 +2343,11 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
 
         /*
          * CTS flow control flag and modem status interrupts
+         * Only disable MSI if no threads are waiting in
+         * serial_core::uart_wait_modem_status
          */
-        up->ier &= ~UART_IER_MSI;
+        if (!waitqueue_active(&up->port.state->port.delta_msr_wait))
+                up->ier &= ~UART_IER_MSI;
         if (!(up->bugs & UART_BUG_NOMSR) &&
                         UART_ENABLE_MS(&up->port, termios->c_cflag))
                 up->ier |= UART_IER_MSI;