tty/serial: lay the foundations for the next set of reworks

- Stop drivers calling their own flush method indirectly, it obfuscates code
  and it will change soon anyway

- A few more lock_kernel paths temporarily needed in some driver internal
  waiting code

- Remove private put_char method that does a write call for one char - we
  have that anyway

- Most but not yet all of the termios copy under lock fixing (some has other
  dependencies to follow)

- Note a few locking bugs in drivers found in the process

- Kill remaining [ab]users of TIOCG/SSOFTCAR in the driver, these must go to
  fix the termios locking

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/char/synclink.c b/drivers/char/synclink.c
index 1c9c440f59ce..dbbd998ae103 100644
--- a/drivers/char/synclink.c
+++ b/drivers/char/synclink.c
@@ -3157,8 +3157,7 @@ static void mgsl_close(struct tty_struct *tty, struct file * filp)
         if (info->flags & ASYNC_INITIALIZED)
                 mgsl_wait_until_sent(tty, info->timeout);
 
-        if (tty->driver->flush_buffer)
-                tty->driver->flush_buffer(tty);
+        mgsl_flush_buffer(tty);
 
         tty_ldisc_flush(tty);
                 
@@ -3221,7 +3220,8 @@ static void mgsl_wait_until_sent(struct tty_struct *tty, int timeout)
          * interval should also be less than the timeout.
          * Note: use tight timings here to satisfy the NIST-PCTS.
          */ 
-       
+
+        lock_kernel();
         if ( info->params.data_rate ) {
                 char_time = info->timeout/(32 * 5);
                 if (!char_time)
@@ -3251,6 +3251,7 @@ static void mgsl_wait_until_sent(struct tty_struct *tty, int timeout)
                                 break;
                 }
         }
+        unlock_kernel();
       
 exit:
         if (debug_level >= DEBUG_LEVEL_INFO)