[PATCH 3/3] staging: dgnc: use tty_alloc_driver instead of kcalloc

From: Daeseok Youn
Date: Mon Mar 14 2016 - 00:29:31 EST


the tty_alloc_driver() can allocate memory for ttys and termios.
And also it can release allocated memory easly with using
put_tty_driver().

Signed-off-by: Daeseok Youn <daeseok.youn@xxxxxxxxx>
---
drivers/staging/dgnc/dgnc_tty.c | 86 +++++++++++++++--------------------------
1 file changed, 31 insertions(+), 55 deletions(-)

diff --git a/drivers/staging/dgnc/dgnc_tty.c b/drivers/staging/dgnc/dgnc_tty.c
index 4e4efa2..118936b 100644
--- a/drivers/staging/dgnc/dgnc_tty.c
+++ b/drivers/staging/dgnc/dgnc_tty.c
@@ -176,9 +176,15 @@ int dgnc_tty_preinit(void)
*/
int dgnc_tty_register(struct dgnc_board *brd)
{
- int rc = 0;
+ int rc;
+
+ brd->serial_driver = tty_alloc_driver(brd->maxports,
+ TTY_DRIVER_REAL_RAW |
+ TTY_DRIVER_DYNAMIC_DEV |
+ TTY_DRIVER_HARDWARE_BREAK);

- brd->serial_driver->magic = TTY_DRIVER_MAGIC;
+ if (IS_ERR(brd->serial_driver))
+ return PTR_ERR(brd->serial_driver);

snprintf(brd->SerialName, MAXTTYNAMELEN, "tty_dgnc_%d_", brd->boardnum);

@@ -186,31 +192,10 @@ int dgnc_tty_register(struct dgnc_board *brd)
brd->serial_driver->name_base = 0;
brd->serial_driver->major = 0;
brd->serial_driver->minor_start = 0;
- brd->serial_driver->num = brd->maxports;
brd->serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
brd->serial_driver->subtype = SERIAL_TYPE_NORMAL;
brd->serial_driver->init_termios = DgncDefaultTermios;
brd->serial_driver->driver_name = DRVSTR;
- brd->serial_driver->flags = (TTY_DRIVER_REAL_RAW |
- TTY_DRIVER_DYNAMIC_DEV |
- TTY_DRIVER_HARDWARE_BREAK);
-
- /*
- * The kernel wants space to store pointers to
- * tty_struct's and termios's.
- */
- brd->serial_driver->ttys = kcalloc(brd->maxports,
- sizeof(*brd->serial_driver->ttys),
- GFP_KERNEL);
- if (!brd->serial_driver->ttys)
- return -ENOMEM;
-
- kref_init(&brd->serial_driver->kref);
- brd->serial_driver->termios = kcalloc(brd->maxports,
- sizeof(*brd->serial_driver->termios),
- GFP_KERNEL);
- if (!brd->serial_driver->termios)
- return -ENOMEM;

/*
* Entry points for driver. Called by the kernel from
@@ -224,7 +209,7 @@ int dgnc_tty_register(struct dgnc_board *brd)
if (rc < 0) {
dev_dbg(&brd->pdev->dev,
"Can't register tty device (%d)\n", rc);
- return rc;
+ goto free_serial_driver;
}
brd->dgnc_Major_Serial_Registered = true;
}
@@ -234,38 +219,26 @@ int dgnc_tty_register(struct dgnc_board *brd)
* again, separately so we don't get the LD confused about what major
* we are when we get into the dgnc_tty_open() routine.
*/
- brd->print_driver->magic = TTY_DRIVER_MAGIC;
+ brd->print_driver = tty_alloc_driver(brd->maxports,
+ TTY_DRIVER_REAL_RAW |
+ TTY_DRIVER_DYNAMIC_DEV |
+ TTY_DRIVER_HARDWARE_BREAK);
+
+ if (IS_ERR(brd->print_driver)) {
+ rc = PTR_ERR(brd->print_driver);
+ goto unregister_serial_driver;
+ }
+
snprintf(brd->PrintName, MAXTTYNAMELEN, "pr_dgnc_%d_", brd->boardnum);

brd->print_driver->name = brd->PrintName;
brd->print_driver->name_base = 0;
brd->print_driver->major = brd->serial_driver->major;
brd->print_driver->minor_start = 0x80;
- brd->print_driver->num = brd->maxports;
brd->print_driver->type = TTY_DRIVER_TYPE_SERIAL;
brd->print_driver->subtype = SERIAL_TYPE_NORMAL;
brd->print_driver->init_termios = DgncDefaultTermios;
brd->print_driver->driver_name = DRVSTR;
- brd->print_driver->flags = (TTY_DRIVER_REAL_RAW |
- TTY_DRIVER_DYNAMIC_DEV |
- TTY_DRIVER_HARDWARE_BREAK);
-
- /*
- * The kernel wants space to store pointers to
- * tty_struct's and termios's. Must be separated from
- * the Serial Driver so we don't get confused
- */
- brd->print_driver->ttys = kcalloc(brd->maxports,
- sizeof(*brd->print_driver->ttys),
- GFP_KERNEL);
- if (!brd->print_driver->ttys)
- return -ENOMEM;
- kref_init(&brd->print_driver->kref);
- brd->print_driver->termios = kcalloc(brd->maxports,
- sizeof(*brd->print_driver->termios),
- GFP_KERNEL);
- if (!brd->print_driver->termios)
- return -ENOMEM;

/*
* Entry points for driver. Called by the kernel from
@@ -280,7 +253,7 @@ int dgnc_tty_register(struct dgnc_board *brd)
dev_dbg(&brd->pdev->dev,
"Can't register Transparent Print device(%d)\n",
rc);
- return rc;
+ goto free_print_driver;
}
brd->dgnc_Major_TransparentPrint_Registered = true;
}
@@ -289,6 +262,15 @@ int dgnc_tty_register(struct dgnc_board *brd)
brd->dgnc_Serial_Major = brd->serial_driver->major;
brd->dgnc_TransparentPrint_Major = brd->print_driver->major;

+ return 0;
+
+free_print_driver:
+ put_tty_driver(brd->print_driver);
+unregister_serial_driver:
+ tty_unregister_driver(brd->serial_driver);
+free_serial_driver:
+ put_tty_driver(brd->serial_driver);
+
return rc;
}

@@ -433,14 +415,8 @@ void dgnc_tty_uninit(struct dgnc_board *brd)
brd->dgnc_Major_TransparentPrint_Registered = false;
}

- kfree(brd->serial_driver->ttys);
- brd->serial_driver->ttys = NULL;
- kfree(brd->serial_driver->termios);
- brd->serial_driver->termios = NULL;
- kfree(brd->print_driver->ttys);
- brd->print_driver->ttys = NULL;
- kfree(brd->print_driver->termios);
- brd->print_driver->termios = NULL;
+ put_tty_driver(brd->serial_driver);
+ put_tty_driver(brd->print_driver);
}

/*
--
1.9.1