TTY: switch tty_flip_buffer_push

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.

IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.

Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 11 insertions, 14 deletions

diff --git a/drivers/tty/rocket.c b/drivers/tty/rocket.c
index 5848a767001a..8073cc0dff59 100644
--- a/drivers/tty/rocket.c
+++ b/drivers/tty/rocket.c
@@ -315,9 +315,8 @@ static inline int rocket_paranoia_check(struct r_port *info,
  *  that receive data is present on a serial port.  Pulls data from FIFO, moves it into the 
  *  tty layer.  
  */
-static void rp_do_receive(struct r_port *info,
-                          struct tty_struct *tty,
-                          CHANNEL_t * cp, unsigned int ChanStatus)
+static void rp_do_receive(struct r_port *info, CHANNEL_t *cp,
+                unsigned int ChanStatus)
 {
         unsigned int CharNStat;
         int ToRecv, wRecv, space;
@@ -416,7 +415,7 @@ static void rp_do_receive(struct r_port *info,
                         cbuf[ToRecv - 1] = sInB(sGetTxRxDataIO(cp));
         }
         /*  Push the data up to the tty layer */
-        tty_flip_buffer_push(tty);
+        tty_flip_buffer_push(&info->port);
 }
 
 /*
@@ -495,7 +494,6 @@ static void rp_do_transmit(struct r_port *info)
 static void rp_handle_port(struct r_port *info)
 {
         CHANNEL_t *cp;
-        struct tty_struct *tty;
         unsigned int IntMask, ChanStatus;
 
         if (!info)
@@ -506,12 +504,7 @@ static void rp_handle_port(struct r_port *info)
                                 "info->flags & NOT_INIT\n");
                 return;
         }
-        tty = tty_port_tty_get(&info->port);
-        if (!tty) {
-                printk(KERN_WARNING "rp: WARNING: rp_handle_port called with "
-                                "tty==NULL\n");
-                return;
-        }
+
         cp = &info->channel;
 
         IntMask = sGetChanIntID(cp) & info->intmask;
@@ -520,7 +513,7 @@ static void rp_handle_port(struct r_port *info)
 #endif
         ChanStatus = sGetChanStatus(cp);
         if (IntMask & RXF_TRIG) {       /* Rx FIFO trigger level */
-                rp_do_receive(info, tty, cp, ChanStatus);
+                rp_do_receive(info, cp, ChanStatus);
         }
         if (IntMask & DELTA_CD) {       /* CD change  */
 #if (defined(ROCKET_DEBUG_OPEN) || defined(ROCKET_DEBUG_INTR) || defined(ROCKET_DEBUG_HANGUP))
@@ -528,10 +521,15 @@ static void rp_handle_port(struct r_port *info)
                        (ChanStatus & CD_ACT) ? "on" : "off");
 #endif
                 if (!(ChanStatus & CD_ACT) && info->cd_status) {
+                        struct tty_struct *tty;
 #ifdef ROCKET_DEBUG_HANGUP
                         printk(KERN_INFO "CD drop, calling hangup.\n");
 #endif
-                        tty_hangup(tty);
+                        tty = tty_port_tty_get(&info->port);
+                        if (tty) {
+                                tty_hangup(tty);
+                                tty_kref_put(tty);
+                        }
                 }
                 info->cd_status = (ChanStatus & CD_ACT) ? 1 : 0;
                 wake_up_interruptible(&info->port.open_wait);
@@ -544,7 +542,6 @@ static void rp_handle_port(struct r_port *info)
                 printk(KERN_INFO "DSR change...\n");
         }
 #endif
-        tty_kref_put(tty);
 }
 
 /*