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| author | Dale Farnsworth <dale@farnsworth.org> | 2007-07-24 11:18:14 -0700 |
|---|---|---|
| committer | Wim Van Sebroeck <wim@iguana.be> | 2007-07-24 21:16:20 +0000 |
| commit | bf2fc92cae3630301d98b9faa38c1a98bb57d801 (patch) | |
| tree | 231e1a56f4072589fcee283a8bcfcb965805e688 /drivers/char/watchdog/mv64x60_wdt.c | |
| parent | d37a5c3ddf7f57fdc0632e279eabb1772f89dfc5 (diff) | |
| download | lwn-bf2fc92cae3630301d98b9faa38c1a98bb57d801.tar.gz lwn-bf2fc92cae3630301d98b9faa38c1a98bb57d801.zip | |
[WATCHDOG] mv64x60_wdt: Support the WDIOF_MAGICCLOSE feature
Disallow disabling of the watchdog timer unless a particular
character ('V') was recently written to the watchdog device.
Signed-off-by: Dale Farnsworth <dale@farnsworth.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/char/watchdog/mv64x60_wdt.c')
| -rw-r--r-- | drivers/char/watchdog/mv64x60_wdt.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/drivers/char/watchdog/mv64x60_wdt.c b/drivers/char/watchdog/mv64x60_wdt.c index 009b9a2c6efa..e07007543d09 100644 --- a/drivers/char/watchdog/mv64x60_wdt.c +++ b/drivers/char/watchdog/mv64x60_wdt.c @@ -44,6 +44,7 @@ static int wdt_status; static void __iomem *mv64x60_wdt_regs; static int mv64x60_wdt_timeout; static unsigned int bus_clk; +static char expect_close; static int nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, int, 0); @@ -115,10 +116,14 @@ static int mv64x60_wdt_open(struct inode *inode, struct file *file) static int mv64x60_wdt_release(struct inode *inode, struct file *file) { - mv64x60_wdt_service(); - - if (!nowayout) + if (expect_close == 42) mv64x60_wdt_handler_disable(); + else { + printk(KERN_CRIT + "mv64x60_wdt: unexpected close, not stopping timer!\n"); + mv64x60_wdt_service(); + } + expect_close = 0; clear_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags); @@ -128,8 +133,22 @@ static int mv64x60_wdt_release(struct inode *inode, struct file *file) static ssize_t mv64x60_wdt_write(struct file *file, const char __user *data, size_t len, loff_t * ppos) { - if (len) + if (len) { + if (!nowayout) { + size_t i; + + expect_close = 0; + + for (i = 0; i != len; i++) { + char c; + if(get_user(c, data + i)) + return -EFAULT; + if (c == 'V') + expect_close = 42; + } + } mv64x60_wdt_service(); + } return len; } @@ -142,6 +161,7 @@ static int mv64x60_wdt_ioctl(struct inode *inode, struct file *file, void __user *argp = (void __user *)arg; static struct watchdog_info info = { .options = WDIOF_SETTIMEOUT | + WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, .firmware_version = 0, .identity = "MV64x60 watchdog", |