Char: tty_ioctl, little whitespace cleanup

[cascardo/linux.git] / drivers / char / tty_ioctl.c

diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c
index dee47f4..3423e9e 100644 (file)
--- a/drivers/char/tty_ioctl.c
+++ b/drivers/char/tty_ioctl.c
@@ -52,8 +52,6 @@
 
 void tty_wait_until_sent(struct tty_struct * tty, long timeout)
 {
-       DECLARE_WAITQUEUE(wait, current);
-
 #ifdef TTY_DEBUG_WAIT_UNTIL_SENT
        char buf[64];
        
@@ -61,26 +59,13 @@ void tty_wait_until_sent(struct tty_struct * tty, long timeout)
 #endif
        if (!tty->driver->chars_in_buffer)
                return;
-       add_wait_queue(&tty->write_wait, &wait);
        if (!timeout)
                timeout = MAX_SCHEDULE_TIMEOUT;
-       do {
-#ifdef TTY_DEBUG_WAIT_UNTIL_SENT
-               printk(KERN_DEBUG "waiting %s...(%d)\n", tty_name(tty, buf),
-                      tty->driver->chars_in_buffer(tty));
-#endif
-               set_current_state(TASK_INTERRUPTIBLE);
-               if (signal_pending(current))
-                       goto stop_waiting;
-               if (!tty->driver->chars_in_buffer(tty))
-                       break;
-               timeout = schedule_timeout(timeout);
-       } while (timeout);
+       if (wait_event_interruptible_timeout(tty->write_wait,
+                       !tty->driver->chars_in_buffer(tty), timeout))
+               return;
        if (tty->driver->wait_until_sent)
                tty->driver->wait_until_sent(tty, timeout);
-stop_waiting:
-       set_current_state(TASK_RUNNING);
-       remove_wait_queue(&tty->write_wait, &wait);
 }
 
 EXPORT_SYMBOL(tty_wait_until_sent);
@@ -225,7 +210,7 @@ EXPORT_SYMBOL(tty_termios_input_baud_rate);
 
 /**
  *     tty_termios_encode_baud_rate
- *     @termios: termios structure
+ *     @termios: ktermios structure holding user requested state
  *     @ispeed: input speed
  *     @ospeed: output speed
  *
@@ -233,7 +218,10 @@ EXPORT_SYMBOL(tty_termios_input_baud_rate);
  *     used as a library helper for drivers os that they can report back
  *     the actual speed selected when it differs from the speed requested
  *
- *     For now input and output speed must agree.
+ *     For maximal back compatibility with legacy SYS5/POSIX *nix behaviour
+ *     we need to carefully set the bits when the user does not get the
+ *     desired speed. We allow small margins and preserve as much of possible
+ *     of the input intent to keep compatiblity.
  *
  *     Locking: Caller should hold termios lock. This is already held
  *     when calling this function from the driver termios handler.
@@ -242,32 +230,43 @@ EXPORT_SYMBOL(tty_termios_input_baud_rate);
 void tty_termios_encode_baud_rate(struct ktermios *termios, speed_t ibaud, speed_t obaud)
 {
        int i = 0;
-       int ifound = 0, ofound = 0;
+       int ifound = -1, ofound = -1;
+       int iclose = ibaud/50, oclose = obaud/50;
+       int ibinput = 0;
 
        termios->c_ispeed = ibaud;
        termios->c_ospeed = obaud;
 
+       /* If the user asked for a precise weird speed give a precise weird
+          answer. If they asked for a Bfoo speed they many have problems
+          digesting non-exact replies so fuzz a bit */
+
+       if ((termios->c_cflag & CBAUD) == BOTHER)
+               oclose = 0;
+       if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER)
+               iclose = 0;
+       if ((termios->c_cflag >> IBSHIFT) & CBAUD)
+               ibinput = 1;    /* An input speed was specified */
+
        termios->c_cflag &= ~CBAUD;
-       /* Identical speed means no input encoding (ie B0 << IBSHIFT)*/
-       if (termios->c_ispeed == termios->c_ospeed)
-               ifound = 1;
 
        do {
-               if (obaud == baud_table[i]) {
+               if (obaud - oclose >= baud_table[i] && obaud + oclose <= baud_table[i]) {
                        termios->c_cflag |= baud_bits[i];
-                       ofound = 1;
-                       /* So that if ibaud == obaud we don't set it */
-                       continue;
+                       ofound = i;
                }
-               if (ibaud == baud_table[i]) {
-                       termios->c_cflag |= (baud_bits[i] << IBSHIFT);
-                       ifound = 1;
+               if (ibaud - iclose >= baud_table[i] && ibaud + iclose <= baud_table[i]) {
+                       /* For the case input == output don't set IBAUD bits if the user didn't do so */
+                       if (ofound != i || ibinput)
+                               termios->c_cflag |= (baud_bits[i] << IBSHIFT);
+                       ifound = i;
                }
-       }
-       while(++i < n_baud_table);
-       if (!ofound)
+       } while (++i < n_baud_table);
+       if (ofound == -1)
                termios->c_cflag |= BOTHER;
-       if (!ifound)
+       /* Set exact input bits only if the input and output differ or the
+          user already did */
+       if (ifound == -1 && (ibaud != obaud || ibinput))
                termios->c_cflag |= (BOTHER << IBSHIFT);
 }
 
@@ -560,7 +559,7 @@ static int set_sgttyb(struct tty_struct * tty, struct sgttyb __user * sgttyb)
                return -EFAULT;
 
        mutex_lock(&tty->termios_mutex);
-       termios =  *tty->termios;
+       termios = *tty->termios;
        termios.c_cc[VERASE] = tmp.sg_erase;
        termios.c_cc[VKILL] = tmp.sg_kill;
        set_sgflags(&termios, tmp.sg_flags);
@@ -652,7 +651,7 @@ static int send_prio_char(struct tty_struct *tty, char ch)
                return 0;
        }
 
-       if (mutex_lock_interruptible(&tty->atomic_write_lock))
+       if (tty_write_lock(tty, 0) < 0)
                return -ERESTARTSYS;
 
        if (was_stopped)
@@ -660,7 +659,7 @@ static int send_prio_char(struct tty_struct *tty, char ch)
        tty->driver->write(tty, &ch, 1);
        if (was_stopped)
                stop_tty(tty);
-       mutex_unlock(&tty->atomic_write_lock);
+       tty_write_unlock(tty);
        return 0;
 }