Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit aa1fd4d7 authored by Wim Van Sebroeck's avatar Wim Van Sebroeck
Browse files

[WATCHDOG] Winbond SMsC37B787 watchdog fixes 



* Added io spinlocking
* Deleted WATCHDOG_MINOR (it's in the miscdevice include
* Changed timer_enabled to use set_bit functions
* WDIOC_GETSUPPORT should return -EFAULT or 0
* timeout should be correct before we initialize the watchdog
* we should initialize the watchdog before we give access
  to userspace
* Third parameter of module_param is not the default or
  initial value

Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
parent 8386c8cf

drivers/char/watchdog/smsc37b787_wdt.c

+30 −17
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ 
#include <linux/notifier.h>

#include <linux/reboot.h>

#include <linux/init.h>

#include <linux/spinlock.h>



#include <asm/io.h>

#include <asm/uaccess.h>
@@ -72,18 +73,18 @@ 
#define MODNAME		"smsc37b787_wdt: "

#define VERSION         "1.1"



#define WATCHDOG_MINOR	130



#define IOPORT          0x3F0

#define IOPORT_SIZE     2

#define IODEV_NO        8



static int unit = UNIT_SECOND;  /* timer's unit */

static int timeout = 60;        /* timeout value: default is 60 "units" */

static int timer_enabled = 0;   /* is the timer enabled? */

static unsigned long timer_enabled = 0;   /* is the timer enabled? */



static char expect_close;       /* is the close expected? */



static spinlock_t io_lock;	/* to guard the watchdog from io races */



static int nowayout = WATCHDOG_NOWAYOUT;



/* -- Low level function ----------------------------------------*/
@@ -210,6 +211,7 @@ static void wb_smsc_wdt_initialize(void) 
{

        unsigned char old;



	spin_lock(&io_lock);

        open_io_config();

        select_io_device(IODEV_NO);
@@ -234,12 +236,14 @@ static void wb_smsc_wdt_initialize(void) 
        wdt_timer_units(old);



        close_io_config();

	spin_unlock(&io_lock);

}



/* shutdown the watchdog */



static void wb_smsc_wdt_shutdown(void)

{

	spin_lock(&io_lock);

        open_io_config();

        select_io_device(IODEV_NO);
@@ -257,12 +261,14 @@ static void wb_smsc_wdt_shutdown(void) 
        wdt_timeout_value(0x00);



        close_io_config();

	spin_unlock(&io_lock);

}



/* set timeout => enable watchdog */



static void wb_smsc_wdt_set_timeout(unsigned char new_timeout)

{

	spin_lock(&io_lock);

        open_io_config();

        select_io_device(IODEV_NO);
@@ -273,6 +279,7 @@ static void wb_smsc_wdt_set_timeout(unsigned char new_timeout) 
        wdt_timeout_value(new_timeout);



        close_io_config();

	spin_unlock(&io_lock);

}



/* get timeout */
@@ -281,10 +288,12 @@ static unsigned char wb_smsc_wdt_get_timeout(void) 
{

        unsigned char set_timeout;



	spin_lock(&io_lock);

        open_io_config();

        select_io_device(IODEV_NO);

        set_timeout = read_io_cr(0xF2);

        close_io_config();

	spin_unlock(&io_lock);



        return set_timeout;

}
@@ -309,6 +318,7 @@ static void wb_smsc_wdt_enable(void) 


static void wb_smsc_wdt_reset_timer(void)

{

	spin_lock(&io_lock);

        open_io_config();

        select_io_device(IODEV_NO);
@@ -317,6 +327,7 @@ static void wb_smsc_wdt_reset_timer(void) 
	wdt_timer_conf(0x08);



        close_io_config();

	spin_unlock(&io_lock);

}



/* return, if the watchdog is enabled (timeout is set...) */
@@ -335,14 +346,13 @@ static int wb_smsc_wdt_open(struct inode *inode, struct file *file) 
{

	/* /dev/watchdog can only be opened once */



	if (timer_enabled)

	if (test_and_set_bit(0, &timer_enabled))

		return -EBUSY;



	if (nowayout)

		__module_get(THIS_MODULE);



	/* Reload and activate timer */

	timer_enabled = 1;

	wb_smsc_wdt_enable();



	printk(KERN_INFO MODNAME "Watchdog enabled. Timeout set to %d %s.\n", timeout, (unit == UNIT_SECOND) ? "second(s)" : "minute(s)");
@@ -364,7 +374,7 @@ static int wb_smsc_wdt_release(struct inode *inode, struct file *file) 
		wb_smsc_wdt_reset_timer();

	}



	timer_enabled = 0;

	clear_bit(0, &timer_enabled);

	expect_close = 0;

	return 0;

}
@@ -425,7 +435,8 @@ static int wb_smsc_wdt_ioctl(struct inode *inode, struct file *file, 
			return -ENOTTY;



		case WDIOC_GETSUPPORT:

			return copy_to_user(uarg.ident, &ident, sizeof(ident));

			return copy_to_user(uarg.ident, &ident,

				sizeof(ident)) ? -EFAULT : 0;



		case WDIOC_GETSTATUS:

			return put_user(wb_smsc_wdt_status(), uarg.i);
@@ -506,12 +517,12 @@ static struct file_operations wb_smsc_wdt_fops = 
	.write		= wb_smsc_wdt_write,

	.ioctl		= wb_smsc_wdt_ioctl,

	.open		= wb_smsc_wdt_open,

	.release	= wb_smsc_wdt_release

	.release	= wb_smsc_wdt_release,

};



static struct notifier_block wb_smsc_wdt_notifier =

{

	.notifier_call  = wb_smsc_wdt_notify_sys

	.notifier_call  = wb_smsc_wdt_notify_sys,

};



static struct miscdevice wb_smsc_wdt_miscdev =
@@ -529,6 +540,8 @@ static int __init wb_smsc_wdt_init(void) 
{

	int ret;



	spin_lock_init(&io_lock);



	printk("SMsC 37B787 watchdog component driver " VERSION " initialising...\n");



	if (!request_region(IOPORT, IOPORT_SIZE, "SMsC 37B787 watchdog")) {
@@ -537,6 +550,13 @@ static int __init wb_smsc_wdt_init(void) 
		goto out_pnp;

	}



        // set new maximum, if it's too big

        if (timeout > MAX_TIMEOUT)

               timeout = MAX_TIMEOUT;



        // init the watchdog timer

        wb_smsc_wdt_initialize();



	ret = register_reboot_notifier(&wb_smsc_wdt_notifier);

	if (ret) {

		printk(KERN_ERR MODNAME "Unable to register reboot notifier err = %d\n", ret);
@@ -549,13 +569,6 @@ static int __init wb_smsc_wdt_init(void) 
		goto out_rbt;

	}



        // init the watchdog timer

        wb_smsc_wdt_initialize();



        // set new maximum, if it's too big

        if (timeout > MAX_TIMEOUT)

               timeout = MAX_TIMEOUT;



	// output info

	printk(KERN_INFO MODNAME "Timeout set to %d %s.\n", timeout, (unit == UNIT_SECOND) ? "second(s)" : "minute(s)");

	printk(KERN_INFO MODNAME "Watchdog initialized and sleeping (nowayout=%d)...\n", nowayout);
@@ -607,7 +620,7 @@ module_param(unit, int, 0); 
MODULE_PARM_DESC(unit, "set unit to use, 0=seconds or 1=minutes, default is 0");

#endif



module_param(timeout, int, 60);

module_param(timeout, int, 0);

MODULE_PARM_DESC(timeout, "range is 1-255 units, default is 60");



module_param(nowayout, int, 0);