TTY: amiserial, simplify set_serial_info

Do not copy whole serial_state. We only need to know whether the speed
is to be changed. Hence store the info in advance and use it later.
A simple bool is enough.

Also remove reduntant assignments and move the tests directly to the
'if'.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 8 insertions, 12 deletions

diff --git a/drivers/tty/amiserial.c b/drivers/tty/amiserial.c
index 410e8e7e6bfe..165cd79faea2 100644
--- a/drivers/tty/amiserial.c
+++ b/drivers/tty/amiserial.c
@@ -1042,21 +1042,19 @@ static int set_serial_info(struct serial_state *state,
                            struct serial_struct __user * new_info)
 {
         struct serial_struct new_serial;
-        struct serial_state old_state;
-        unsigned int            change_irq,change_port;
+        bool change_spd;
         int                     retval = 0;
 
         if (copy_from_user(&new_serial,new_info,sizeof(new_serial)))
                 return -EFAULT;
 
         tty_lock();
-        old_state = *state;
-  
-        change_irq = new_serial.irq != state->irq;
-        change_port = (new_serial.port != state->port);
-        if(change_irq || change_port || (new_serial.xmit_fifo_size != state->xmit_fifo_size)) {
-          tty_unlock();
-          return -EINVAL;
+        change_spd = ((new_serial.flags ^ state->flags) & ASYNC_SPD_MASK) ||
+                new_serial.custom_divisor != state->custom_divisor;
+        if (new_serial.irq != state->irq || new_serial.port != state->port ||
+                        new_serial.xmit_fifo_size != state->xmit_fifo_size) {
+                tty_unlock();
+                return -EINVAL;
         }
   
         if (!serial_isroot()) {
@@ -1092,9 +1090,7 @@ static int set_serial_info(struct serial_state *state,
 
 check_and_exit:
         if (state->flags & ASYNC_INITIALIZED) {
-                if (((old_state.flags & ASYNC_SPD_MASK) !=
-                     (state->flags & ASYNC_SPD_MASK)) ||
-                    (old_state.custom_divisor != state->custom_divisor)) {
+                if (change_spd) {
                         if ((state->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
                                 state->tty->alt_speed = 57600;
                         if ((state->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)