Signed-off-by: Baodong Chen <[email protected]>
---
drivers/staging/net/pc300_tty.c | 55 ++++++++++++++++++++++-----------------
1 files changed, 31 insertions(+), 24 deletions(-)
diff --git a/drivers/staging/net/pc300_tty.c b/drivers/staging/net/pc300_tty.c
index 4709f42..91ada93 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! ",
@@ -408,13 +426,9 @@ static void cpc_tty_close(struct tty_struct *tty, struct
file *flip)
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);
- }
+ 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;
}
@@ -644,13 +658,9 @@ static void cpc_tty_hangup(struct tty_struct *tty)
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);
}
@@ -1043,19 +1053,16 @@ void cpc_tty_unregister_service(pc300dev_t *pc300dev)
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);
--
1.7.0.4
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