tty: rework break handling

Some hardware needs to do break handling itself and may have partial
support only. Make break_ctl return an error code. Add a tty driver flag
so you can indicate driver hardware side break support.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 5 deletions

diff --git a/drivers/char/istallion.c b/drivers/char/istallion.c
index 7930fba4bafc..63d22b5ebc0d 100644
--- a/drivers/char/istallion.c
+++ b/drivers/char/istallion.c
@@ -609,7 +609,7 @@ static void	stli_unthrottle(struct tty_struct *tty);
 static void     stli_stop(struct tty_struct *tty);
 static void     stli_start(struct tty_struct *tty);
 static void     stli_flushbuffer(struct tty_struct *tty);
-static void     stli_breakctl(struct tty_struct *tty, int state);
+static int      stli_breakctl(struct tty_struct *tty, int state);
 static void     stli_waituntilsent(struct tty_struct *tty, int timeout);
 static void     stli_sendxchar(struct tty_struct *tty, char ch);
 static void     stli_hangup(struct tty_struct *tty);
@@ -1909,7 +1909,7 @@ static void stli_flushbuffer(struct tty_struct *tty)
 
 /*****************************************************************************/
 
-static void stli_breakctl(struct tty_struct *tty, int state)
+static int stli_breakctl(struct tty_struct *tty, int state)
 {
         struct stlibrd  *brdp;
         struct stliport *portp;
@@ -1917,15 +1917,16 @@ static void stli_breakctl(struct tty_struct *tty, int state)
 
         portp = tty->driver_data;
         if (portp == NULL)
-                return;
+                return -EINVAL;
         if (portp->brdnr >= stli_nrbrds)
-                return;
+                return -EINVAL;
         brdp = stli_brds[portp->brdnr];
         if (brdp == NULL)
-                return;
+                return -EINVAL;
 
         arg = (state == -1) ? BREAKON : BREAKOFF;
         stli_cmdwait(brdp, portp, A_BREAK, &arg, sizeof(long), 0);
+        return 0;
 }
 
 /*****************************************************************************/