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| author | Alan Cox <alan@redhat.com> | 2008-08-04 17:53:22 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-08-04 17:12:07 -0700 |
| commit | 670d59c0ae31a872341785b1d93add284c1653ff (patch) | |
| tree | f416b40c99a0449a47d60d24e803403f1b1b8f4f | |
| parent | d5cae364148088911bdf007a8aaefb46a92f16f7 (diff) | |
| download | linux-3.10-670d59c0ae31a872341785b1d93add284c1653ff.tar.gz linux-3.10-670d59c0ae31a872341785b1d93add284c1653ff.tar.bz2 linux-3.10-670d59c0ae31a872341785b1d93add284c1653ff.zip | |
ar7_wdt watchdog driver: Fix locking
Use unlocked_ioctl
Remove semaphores
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/watchdog/ar7_wdt.c | 29 |
1 files changed, 17 insertions, 12 deletions
diff --git a/drivers/watchdog/ar7_wdt.c b/drivers/watchdog/ar7_wdt.c index 2eb48c0df32..ef7b0d67095 100644 --- a/drivers/watchdog/ar7_wdt.c +++ b/drivers/watchdog/ar7_wdt.c @@ -69,7 +69,8 @@ struct ar7_wdt { u32 prescale; }; -static struct semaphore open_semaphore; +static unsigned long wdt_is_open; +static spinlock_t wdt_lock; static unsigned expect_close; /* XXX currently fixed, allows max margin ~68.72 secs */ @@ -154,8 +155,10 @@ static void ar7_wdt_update_margin(int new_margin) u32 change; change = new_margin * (ar7_vbus_freq() / prescale_value); - if (change < 1) change = 1; - if (change > 0xffff) change = 0xffff; + if (change < 1) + change = 1; + if (change > 0xffff) + change = 0xffff; ar7_wdt_change(change); margin = change * prescale_value / ar7_vbus_freq(); printk(KERN_INFO DRVNAME @@ -179,7 +182,7 @@ static void ar7_wdt_disable_wdt(void) static int ar7_wdt_open(struct inode *inode, struct file *file) { /* only allow one at a time */ - if (down_trylock(&open_semaphore)) + if (test_and_set_bit(0, &wdt_is_open)) return -EBUSY; ar7_wdt_enable_wdt(); expect_close = 0; @@ -195,9 +198,7 @@ static int ar7_wdt_release(struct inode *inode, struct file *file) "will not disable the watchdog timer\n"); else if (!nowayout) ar7_wdt_disable_wdt(); - - up(&open_semaphore); - + clear_bit(0, &wdt_is_open); return 0; } @@ -222,7 +223,9 @@ static ssize_t ar7_wdt_write(struct file *file, const char *data, if (len) { size_t i; + spin_lock(&wdt_lock); ar7_wdt_kick(1); + spin_unlock(&wdt_lock); expect_close = 0; for (i = 0; i < len; ++i) { @@ -237,8 +240,8 @@ static ssize_t ar7_wdt_write(struct file *file, const char *data, return len; } -static int ar7_wdt_ioctl(struct inode *inode, struct file *file, - unsigned int cmd, unsigned long arg) +static long ar7_wdt_ioctl(struct file *file, + unsigned int cmd, unsigned long arg) { static struct watchdog_info ident = { .identity = LONGNAME, @@ -269,8 +272,10 @@ static int ar7_wdt_ioctl(struct inode *inode, struct file *file, if (new_margin < 1) return -EINVAL; + spin_lock(&wdt_lock); ar7_wdt_update_margin(new_margin); ar7_wdt_kick(1); + spin_unlock(&wdt_lock); case WDIOC_GETTIMEOUT: if (put_user(margin, (int *)arg)) @@ -282,7 +287,7 @@ static int ar7_wdt_ioctl(struct inode *inode, struct file *file, static const struct file_operations ar7_wdt_fops = { .owner = THIS_MODULE, .write = ar7_wdt_write, - .ioctl = ar7_wdt_ioctl, + .unlocked_ioctl = ar7_wdt_ioctl, .open = ar7_wdt_open, .release = ar7_wdt_release, }; @@ -297,6 +302,8 @@ static int __init ar7_wdt_init(void) { int rc; + spin_lock_init(&wdt_lock); + ar7_wdt_get_regs(); if (!request_mem_region(ar7_regs_wdt, sizeof(struct ar7_wdt), @@ -312,8 +319,6 @@ static int __init ar7_wdt_init(void) ar7_wdt_prescale(prescale_value); ar7_wdt_update_margin(margin); - sema_init(&open_semaphore, 1); - rc = register_reboot_notifier(&ar7_wdt_notifier); if (rc) { printk(KERN_ERR DRVNAME |