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Subject[PATCH 34/68] TTY: amiserial, simplify set_serial_info
Date
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>
---
drivers/tty/amiserial.c | 20 ++++++++------------
1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/tty/amiserial.c b/drivers/tty/amiserial.c
index 410e8e7..165cd79 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)
--
1.7.9.2



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