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| author | Timur Tabi <timur@freescale.com> | 2010-12-03 10:51:43 -0600 |
|---|---|---|
| committer | Wim Van Sebroeck <wim@iguana.be> | 2011-01-12 10:24:27 +0000 |
| commit | 5d63c13415db2819590bba975dd023eaa593ddc3 (patch) | |
| tree | c1a99558bd8d6f74f1f3753bf7e8d2a56c27fd20 | |
| parent | a787e71068d7c2e438d8a5a38a7e1385389819f0 (diff) | |
| download | linux-5d63c13415db2819590bba975dd023eaa593ddc3.tar.gz linux-5d63c13415db2819590bba975dd023eaa593ddc3.tar.bz2 linux-5d63c13415db2819590bba975dd023eaa593ddc3.zip | |
watchdog: add CONFIG_WATCHDOG_NOWAYOUT support to PowerPC Book-E watchdog driver
Normally, the watchdog is disabled when dev/watchdog is closed, but if
CONFIG_WATCHDOG_NOWAYOUT is defined, then it means that the watchdog should
remain enabled. So we should disable it only if CONFIG_WATCHDOG_NOWAYOUT is
not defined.
Also ensure that /dev/watchdog is only opened by one process at a time. That
way, a second process can't accidentally disable the watchdog while the first
process has it open. There shouldn't be any need for more than one process to
open /dev/watchdog anyway.
Signed-off-by: Timur Tabi <timur@freescale.com>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
| -rw-r--r-- | drivers/watchdog/booke_wdt.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/watchdog/booke_wdt.c b/drivers/watchdog/booke_wdt.c index d11ffb091b0d..636e013e221e 100644 --- a/drivers/watchdog/booke_wdt.c +++ b/drivers/watchdog/booke_wdt.c @@ -193,8 +193,15 @@ static long booke_wdt_ioctl(struct file *file, return 0; } +/* wdt_is_active stores wether or not the /dev/watchdog device is opened */ +static unsigned long wdt_is_active; + static int booke_wdt_open(struct inode *inode, struct file *file) { + /* /dev/watchdog can only be opened once */ + if (test_and_set_bit(0, &wdt_is_active)) + return -EBUSY; + spin_lock(&booke_wdt_lock); if (booke_wdt_enabled == 0) { booke_wdt_enabled = 1; @@ -210,8 +217,17 @@ static int booke_wdt_open(struct inode *inode, struct file *file) static int booke_wdt_release(struct inode *inode, struct file *file) { +#ifndef CONFIG_WATCHDOG_NOWAYOUT + /* Normally, the watchdog is disabled when /dev/watchdog is closed, but + * if CONFIG_WATCHDOG_NOWAYOUT is defined, then it means that the + * watchdog should remain enabled. So we disable it only if + * CONFIG_WATCHDOG_NOWAYOUT is not defined. + */ on_each_cpu(__booke_wdt_disable, NULL, 0); booke_wdt_enabled = 0; +#endif + + clear_bit(0, &wdt_is_active); return 0; } |