tty: introduce wait_event_interruptible_tty

Calling wait_event_interruptible implicitly
releases the BKL when it sleeps, but we need
to do this explcitly when we have converted
it to a mutex.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 8 insertions, 4 deletions

diff --git a/drivers/char/istallion.c b/drivers/char/istallion.c
index 5e9a81d8ebcf..be28391adb79 100644
--- a/drivers/char/istallion.c
+++ b/drivers/char/istallion.c
@@ -954,7 +954,7 @@ static int stli_rawopen(struct stlibrd *brdp, struct stliport *portp, unsigned l
  *      order of opens and closes may not be preserved across shared
  *      memory, so we must wait until it is complete.
  */
-        wait_event_interruptible(portp->raw_wait,
+        wait_event_interruptible_tty(portp->raw_wait,
                         !test_bit(ST_CLOSING, &portp->state));
         if (signal_pending(current)) {
                 return -ERESTARTSYS;
@@ -989,7 +989,7 @@ static int stli_rawopen(struct stlibrd *brdp, struct stliport *portp, unsigned l
         set_bit(ST_OPENING, &portp->state);
         spin_unlock_irqrestore(&brd_lock, flags);
 
-        wait_event_interruptible(portp->raw_wait,
+        wait_event_interruptible_tty(portp->raw_wait,
                         !test_bit(ST_OPENING, &portp->state));
         if (signal_pending(current))
                 rc = -ERESTARTSYS;
@@ -1020,7 +1020,7 @@ static int stli_rawclose(struct stlibrd *brdp, struct stliport *portp, unsigned
  *      occurs on this port.
  */
         if (wait) {
-                wait_event_interruptible(portp->raw_wait,
+                wait_event_interruptible_tty(portp->raw_wait,
                                 !test_bit(ST_CLOSING, &portp->state));
                 if (signal_pending(current)) {
                         return -ERESTARTSYS;
@@ -1052,7 +1052,7 @@ static int stli_rawclose(struct stlibrd *brdp, struct stliport *portp, unsigned
  *      to come back.
  */
         rc = 0;
-        wait_event_interruptible(portp->raw_wait,
+        wait_event_interruptible_tty(portp->raw_wait,
                         !test_bit(ST_CLOSING, &portp->state));
         if (signal_pending(current))
                 rc = -ERESTARTSYS;
@@ -1073,6 +1073,10 @@ static int stli_rawclose(struct stlibrd *brdp, struct stliport *portp, unsigned
 
 static int stli_cmdwait(struct stlibrd *brdp, struct stliport *portp, unsigned long cmd, void *arg, int size, int copyback)
 {
+        /*
+         * no need for wait_event_tty because clearing ST_CMDING cannot block
+         * on BTM
+         */
         wait_event_interruptible(portp->raw_wait,
                         !test_bit(ST_CMDING, &portp->state));
         if (signal_pending(current))