diff options
| author | Peter Hurley <peter@hurleysoftware.com> | 2015-01-22 20:24:31 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-02-02 21:11:27 +0300 |
| commit | e9cef8625e997a5ade9cddd2d501257dfee7cb62 (patch) | |
| tree | b76b44f9d048028855a3233e02c1d03515b87676 /drivers/tty | |
| parent | 4516d50aabedbe5ae334155193e4d35c02390d9a (diff) | |
| download | linux-e9cef8625e997a5ade9cddd2d501257dfee7cb62.tar.xz | |
serial: 8250: Prevent concurrent updates to shadow registers
The port shadow registers, ->fcr and ->mcr, must be protected from
concurrent updates. Relocate the shadow register updates in
serial8250_do_set_termios() to the port lock critical section.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/8250/8250_core.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 1449c56506b7..57d13b058a48 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -2549,6 +2549,15 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios, port->uartclk / 16); quot = serial8250_get_divisor(up, baud, &frac); + /* + * Ok, we're now changing the port state. Do it with + * interrupts disabled. + */ + serial8250_rpm_get(up); + spin_lock_irqsave(&port->lock, flags); + + up->lcr = cval; /* Save computed LCR */ + if (up->capabilities & UART_CAP_FIFO && port->fifosize > 1) { /* NOTE: If fifo_bug is not set, a user can set RX_trigger. */ if ((baud < 2400 && !up->dma) || up->fifo_bug) { @@ -2572,15 +2581,6 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios, } /* - * Ok, we're now changing the port state. Do it with - * interrupts disabled. - */ - serial8250_rpm_get(up); - spin_lock_irqsave(&port->lock, flags); - - up->lcr = cval; /* Save computed LCR */ - - /* * Update the per-port timeout. */ uart_update_timeout(port, termios->c_cflag, baud); |