TTY: n_gsm, use tty_port_install

We need to link a port to a tty in install. And since dlci is
allocated even in open, we need to create gsmtty_install, allocate
dlci there and create also the link.

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

1 files changed, 24 insertions, 6 deletions

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 7a4bf3053a15..3778687f748b 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2868,14 +2868,14 @@ static const struct tty_port_operations gsm_port_ops = {
         .dtr_rts = gsm_dtr_rts,
 };
 
-
-static int gsmtty_open(struct tty_struct *tty, struct file *filp)
+static int gsmtty_install(struct tty_driver *driver, struct tty_struct *tty)
 {
         struct gsm_mux *gsm;
         struct gsm_dlci *dlci;
-        struct tty_port *port;
         unsigned int line = tty->index;
         unsigned int mux = line >> 6;
+        bool alloc = false;
+        int ret;
 
         line = line & 0x3F;
 
@@ -2890,13 +2890,30 @@ static int gsmtty_open(struct tty_struct *tty, struct file *filp)
         if (gsm->dead)
                 return -EL2HLT;
         dlci = gsm->dlci[line];
-        if (dlci == NULL)
+        if (dlci == NULL) {
+                alloc = true;
                 dlci = gsm_dlci_alloc(gsm, line);
+        }
         if (dlci == NULL)
                 return -ENOMEM;
-        port = &dlci->port;
-        port->count++;
+        ret = tty_port_install(&dlci->port, driver, tty);
+        if (ret) {
+                if (alloc)
+                        dlci_put(dlci);
+                return ret;
+        }
+
         tty->driver_data = dlci;
+
+        return 0;
+}
+
+static int gsmtty_open(struct tty_struct *tty, struct file *filp)
+{
+        struct gsm_dlci *dlci = tty->driver_data;
+        struct tty_port *port = &dlci->port;
+
+        port->count++;
         dlci_get(dlci);
         dlci_get(dlci->gsm->dlci[0]);
         mux_get(dlci->gsm);
@@ -3085,6 +3102,7 @@ static int gsmtty_break_ctl(struct tty_struct *tty, int state)
 
 /* Virtual ttys for the demux */
 static const struct tty_operations gsmtty_ops = {
+        .install                = gsmtty_install,
         .open                   = gsmtty_open,
         .close                  = gsmtty_close,
         .write                  = gsmtty_write,