tty: isicom: sort out the board init logic

Split this into two flags - INIT meaning the board is set up and ACTIVE
meaning the board has ports open. Remove the broken HUPCL casing and push
the counts somewhere sensible.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 11 insertions, 30 deletions

diff --git a/drivers/char/isicom.c b/drivers/char/isicom.c
index e7be3ec6d21c..1e91c302ee42 100644
--- a/drivers/char/isicom.c
+++ b/drivers/char/isicom.c
@@ -793,21 +793,19 @@ static inline void isicom_setup_board(struct isi_board *bp)
 {
         int channel;
         struct isi_port *port;
-        unsigned long flags;
 
-        spin_lock_irqsave(&bp->card_lock, flags);
-        if (bp->status & BOARD_ACTIVE) {
-                spin_unlock_irqrestore(&bp->card_lock, flags);
-                return;
-        }
-        port = bp->ports;
-        bp->status |= BOARD_ACTIVE;
-        for (channel = 0; channel < bp->port_count; channel++, port++)
-                drop_dtr_rts(port);
         bp->count++;
-        spin_unlock_irqrestore(&bp->card_lock, flags);
+        if (!(bp->status & BOARD_INIT)) {
+                port = bp->ports;
+                for (channel = 0; channel < bp->port_count; channel++, port++)
+                        drop_dtr_rts(port);
+        }
+        bp->status |= BOARD_ACTIVE | BOARD_INIT;
 }
 
+/* Activate and thus setup board are protected from races against shutdown
+   by the tty_port mutex */
+
 static int isicom_activate(struct tty_port *tport, struct tty_struct *tty)
 {
         struct isi_port *port = container_of(tport, struct isi_port, port);
@@ -884,19 +882,10 @@ static int isicom_open(struct tty_struct *tty, struct file *filp)
 
 /* close et all */
 
-static inline void isicom_shutdown_board(struct isi_board *bp)
-{
-        if (bp->status & BOARD_ACTIVE)
-                bp->status &= ~BOARD_ACTIVE;
-}
-
 /* card->lock HAS to be held */
 static void isicom_shutdown_port(struct isi_port *port)
 {
         struct isi_board *card = port->card;
-        struct tty_struct *tty;
-
-        tty = tty_port_tty_get(&port->port);
 
         tty_port_free_xmit_buf(&port->port);
         if (--card->count < 0) {
@@ -904,17 +893,9 @@ static void isicom_shutdown_port(struct isi_port *port)
                         card->base, card->count);
                 card->count = 0;
         }
-
         /* last port was closed, shutdown that board too */
-        if (tty && C_HUPCL(tty)) {
-                /* FIXME: this logic is bogus - it's the old logic that was
-                   bogus before but it still wants fixing */
-                if (!card->count) {
-                        if (card->status & BOARD_ACTIVE)
-                                card->status &= ~BOARD_ACTIVE;
-                }
-        }
-        tty_kref_put(tty);
+        if (!card->count)
+                card->status &= BOARD_ACTIVE;
 }
 
 static void isicom_flush_buffer(struct tty_struct *tty)