Fixed code to fix tty_driver's kref field
Coding style issues

Signed-off-by: Baodong Chen <[email protected]>
---
 drivers/staging/net/pc300_tty.c |  123 ++++++++++++++++++++------------------
 1 files changed, 65 insertions(+), 58 deletions(-)

diff --git a/drivers/staging/net/pc300_tty.c b/drivers/staging/net/pc300_tty.c
index 4709f42..8a7277c 100644
--- a/drivers/staging/net/pc300_tty.c
+++ b/drivers/staging/net/pc300_tty.c
@@ -46,6 +46,8 @@
 #include <linux/slab.h>
 #include <linux/if.h>
 #include <linux/skbuff.h>
+#include <linux/kref.h>
+
 /* TTY includes */
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
@@ -134,12 +136,26 @@ static void cpc_tty_signal_on(pc300dev_t *pc300dev, 
unsigned char);
 static int pc300_tiocmset(struct tty_struct *, unsigned int, unsigned int);
 static int pc300_tiocmget(struct tty_struct *);
 
+static void cpc_tty_do_unreg_driver(struct kref *ref);
+
 /* functions called by PC300 driver */
 void cpc_tty_init(pc300dev_t *dev);
 void cpc_tty_unregister_service(pc300dev_t *pc300dev);
 void cpc_tty_receive(pc300dev_t *pc300dev);
 void cpc_tty_trigger_poll(pc300dev_t *pc300dev);
 
+static void cpc_tty_do_unreg_driver(struct kref *ref)
+{
+       struct tty_driver *drv = container_of(ref, struct tty_driver, kref);
+       int ret;
+
+       cpc_tty_unreg_flag = 0;
+
+       res = tty_unregister_driver(drv);
+       if (res)
+               CPC_TTY_DBG("unregister the tty driver error=%d\n", res);
+}
+
 /*
  * PC300 TTY clear "signal"
  */
@@ -239,6 +255,8 @@ void cpc_tty_init(pc300dev_t *pc300dev)
                /* interface routines from the upper tty layer to the tty 
driver */
                tty_set_operations(&serial_drv, &pc300_ops);
 
+               kref_init(&serial_drv.kref);
+
                /* register the TTY driver */
                if (tty_register_driver(&serial_drv)) { 
                        printk("%s-tty: Failed to register serial driver! ",
@@ -363,37 +381,37 @@ static void cpc_tty_close(struct tty_struct *tty, struct 
file *flip)
        unsigned long flags;
        int res;
 
-       if (!tty || !tty->driver_data ) {
+       if (!tty || !tty->driver_data) {
                CPC_TTY_DBG("hdlx-tty: no TTY in close\n");
                return;
        }
 
        cpc_tty = (st_cpc_tty_area *) tty->driver_data;
 
-       if ((cpc_tty->tty != tty)|| (cpc_tty->state != CPC_TTY_ST_OPEN)) {
-               CPC_TTY_DBG("%s: TTY is not opened\n",cpc_tty->name);
+       if ((cpc_tty->tty != tty) || (cpc_tty->state != CPC_TTY_ST_OPEN)) {
+               CPC_TTY_DBG("%s: TTY is not opened\n", cpc_tty->name);
                return;
        }
-       
+
        if (!cpc_tty->num_open) {
-               CPC_TTY_DBG("%s: TTY is closed\n",cpc_tty->name);
+               CPC_TTY_DBG("%s: TTY is closed\n", cpc_tty->name);
                return;
        }
 
        if (--cpc_tty->num_open > 0) {
-               CPC_TTY_DBG("%s: TTY closed\n",cpc_tty->name);
+               CPC_TTY_DBG("%s: TTY closed\n", cpc_tty->name);
                return;
        }
 
        cpc_tty_signal_off(cpc_tty->pc300dev, CTL_DTR);
 
-       CPC_TTY_LOCK(cpc_tty->pc300dev->chan->card, flags);  /* lock irq */ 
+       CPC_TTY_LOCK(cpc_tty->pc300dev->chan->card, flags);  /* lock irq */
        cpc_tty->tty = NULL;
        cpc_tty->state = CPC_TTY_ST_INIT;
-       CPC_TTY_UNLOCK(cpc_tty->pc300dev->chan->card, flags); /* unlock irq */ 
-       
+       CPC_TTY_UNLOCK(cpc_tty->pc300dev->chan->card, flags); /* unlock irq */
+
        if (cpc_tty->buf_rx.first) {
-               unsigned char * aux;
+               unsigned char *aux;
                while (cpc_tty->buf_rx.first) {
                        aux = (unsigned char *)cpc_tty->buf_rx.first;
                        cpc_tty->buf_rx.first = cpc_tty->buf_rx.first->next;
@@ -402,22 +420,18 @@ static void cpc_tty_close(struct tty_struct *tty, struct 
file *flip)
                cpc_tty->buf_rx.first = NULL;
                cpc_tty->buf_rx.last = NULL;
        }
-       
+
        kfree(cpc_tty->buf_tx);
        cpc_tty->buf_tx = NULL;
 
-       CPC_TTY_DBG("%s: TTY closed\n",cpc_tty->name);
-       
-       if (!serial_drv.refcount && cpc_tty_unreg_flag) {
-               cpc_tty_unreg_flag = 0;
-               CPC_TTY_DBG("%s: unregister the tty driver\n", cpc_tty->name);
-               if ((res=tty_unregister_driver(&serial_drv))) { 
-                       CPC_TTY_DBG("%s: ERROR ->unregister the tty driver 
error=%d\n",
-                                                       cpc_tty->name,res);
-               }
+       CPC_TTY_DBG("%s: TTY closed\n", cpc_tty->name);
+
+       if (cpc_tty_unreg_flag) {
+               CPC_TTY_DBG("%s: checking unregister the tty driver...\n", 
cpc_tty->name);
+               kref_put(&serial_drv.kref, cpc_tty_do_unreg_driver);
        }
-       return; 
-} 
+       return;
+}
 
 /*
  * PC300 TTY WRITE routine
@@ -624,33 +638,29 @@ static void cpc_tty_flush_buffer(struct tty_struct *tty)
 /*
  * PC300 TTY Hangup routine
  *
- * This routine is called by the tty driver to hangup the interface 
+ * This routine is called by the tty driver to hangup the interface
  * o clear DTR signal
  */
 
 static void cpc_tty_hangup(struct tty_struct *tty)
-{ 
-       st_cpc_tty_area    *cpc_tty; 
+{
+       st_cpc_tty_area    *cpc_tty;
        int res;
 
-       if (!tty || !tty->driver_data ) {
-               CPC_TTY_DBG("hdlcX-tty: no TTY to hangup\n");   
-               return ; 
+       if (!tty || !tty->driver_data) {
+               CPC_TTY_DBG("hdlcX-tty: no TTY to hangup\n");
+               return ;
        }
 
-       cpc_tty = (st_cpc_tty_area *) tty->driver_data; 
+       cpc_tty = (st_cpc_tty_area *) tty->driver_data;
 
        if ((cpc_tty->tty != tty) || (cpc_tty->state != CPC_TTY_ST_OPEN)) {
-               CPC_TTY_DBG("%s: TTY is not opened\n",cpc_tty->name);
+               CPC_TTY_DBG("%s: TTY is not opened\n", cpc_tty->name);
                return ;
        }
-       if (!serial_drv.refcount && cpc_tty_unreg_flag) {
-               cpc_tty_unreg_flag = 0;
-               CPC_TTY_DBG("%s: unregister the tty driver\n", cpc_tty->name);
-               if ((res=tty_unregister_driver(&serial_drv))) { 
-                       CPC_TTY_DBG("%s: ERROR ->unregister the tty driver 
error=%d\n",
-                                                       cpc_tty->name,res);
-               }
+       if (cpc_tty_unreg_flag) {
+               CPC_TTY_DBG("%s: checking unregister the tty driver...\n", 
cpc_tty->name);
+               kref_put(&serial_drv.kref, cpc_tty_do_unreg_driver);
        }
        cpc_tty_signal_off(cpc_tty->pc300dev, CTL_DTR);
 }
@@ -1027,43 +1037,40 @@ static void cpc_tty_trace(pc300dev_t *dev, char* buf, 
int len, char rxtx)
  */
 void cpc_tty_unregister_service(pc300dev_t *pc300dev)
 {
-       st_cpc_tty_area *cpc_tty; 
+       st_cpc_tty_area *cpc_tty = (st_cpc_tty_area *) pc300dev->cpc_tty;
        ulong flags;
        int res;
 
-       if ((cpc_tty= (st_cpc_tty_area *) pc300dev->cpc_tty) == NULL) {
+       if (cpc_tty == NULL) {
                CPC_TTY_DBG("%s: interface is not TTY\n", pc300dev->dev->name);
-               return; 
+               return;
        }
        CPC_TTY_DBG("%s: cpc_tty_unregister_service", cpc_tty->name);
 
-       if (cpc_tty->pc300dev != pc300dev) { 
-               CPC_TTY_DBG("%s: invalid tty ptr=%s\n", 
+       if (cpc_tty->pc300dev != pc300dev) {
+               CPC_TTY_DBG("%s: invalid tty ptr=%s\n",
                pc300dev->dev->name, cpc_tty->name);
-               return; 
+               return;
        }
 
-       if (--cpc_tty_cnt == 0) { 
-               if (serial_drv.refcount) {
-                       CPC_TTY_DBG("%s: unregister is not possible, 
refcount=%d",
-                                                       cpc_tty->name, 
serial_drv.refcount);
+       if (--cpc_tty_cnt == 0) {
+               CPC_TTY_DBG("%s: checking unregister the tty driver...\n",
+                               cpc_tty->name);
+               res = kref_put(&serial_drv.kref, cpc_tty_do_unreg_driver);
+               if (0 == res) {
+                       CPC_TTY_DBG("%s: unregister is not possible\n",
+                                       cpc_tty->name);
                        cpc_tty_cnt++;
                        cpc_tty_unreg_flag = 1;
                        return;
-               } else { 
-                       CPC_TTY_DBG("%s: unregister the tty driver\n", 
cpc_tty->name);
-                       if ((res=tty_unregister_driver(&serial_drv))) { 
-                               CPC_TTY_DBG("%s: ERROR ->unregister the tty 
driver error=%d\n",
-                                                               
cpc_tty->name,res);
-                       }
                }
        }
-       CPC_TTY_LOCK(pc300dev->chan->card,flags);
-       cpc_tty->tty = NULL; 
+       CPC_TTY_LOCK(pc300dev->chan->card, flags);
+       cpc_tty->tty = NULL;
        CPC_TTY_UNLOCK(pc300dev->chan->card, flags);
-       cpc_tty->tty_minor = 0; 
-       cpc_tty->state = CPC_TTY_ST_IDLE; 
-} 
+       cpc_tty->tty_minor = 0;
+       cpc_tty->state = CPC_TTY_ST_IDLE;
+}
 
 /*
  * PC300 TTY trigger poll routine
-- 
1.7.0.4

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