Messages in this thread | | | Subject | Re: [PATCH 3/5] watchdog: sp805: set WDOG_HW_RUNNING when appropriate | From | Scott Branden <> | Date | Wed, 23 May 2018 00:52:27 -0700 |
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On 18-05-22 04:24 PM, Ray Jui wrote: > Hi Guenter, > > On 5/22/2018 1:54 PM, Guenter Roeck wrote: >> On Tue, May 22, 2018 at 11:47:18AM -0700, Ray Jui wrote: >>> If the watchdog hardware is already enabled during the boot process, >>> when the Linux watchdog driver loads, it should reset the watchdog and >>> tell the watchdog framework. As a result, ping can be generated from >>> the watchdog framework, until the userspace watchdog daemon takes over >>> control >>> >>> Signed-off-by: Ray Jui <ray.jui@broadcom.com> >>> Reviewed-by: Vladimir Olovyannikov <vladimir.olovyannikov@broadcom.com> >>> Reviewed-by: Scott Branden <scott.branden@broadcom.com> >>> --- >>> drivers/watchdog/sp805_wdt.c | 22 ++++++++++++++++++++++ >>> 1 file changed, 22 insertions(+) >>> >>> diff --git a/drivers/watchdog/sp805_wdt.c >>> b/drivers/watchdog/sp805_wdt.c >>> index 1484609..408ffbe 100644 >>> --- a/drivers/watchdog/sp805_wdt.c >>> +++ b/drivers/watchdog/sp805_wdt.c >>> @@ -42,6 +42,7 @@ >>> /* control register masks */ >>> #define INT_ENABLE (1 << 0) >>> #define RESET_ENABLE (1 << 1) >>> + #define ENABLE_MASK (INT_ENABLE | RESET_ENABLE) >>> #define WDTINTCLR 0x00C >>> #define WDTRIS 0x010 >>> #define WDTMIS 0x014 >>> @@ -74,6 +75,18 @@ module_param(nowayout, bool, 0); >>> MODULE_PARM_DESC(nowayout, >>> "Set to 1 to keep watchdog running after device release"); >>> +/* returns true if wdt is running; otherwise returns false */ >>> +static bool wdt_is_running(struct watchdog_device *wdd) >>> +{ >>> + struct sp805_wdt *wdt = watchdog_get_drvdata(wdd); >>> + >>> + if ((readl_relaxed(wdt->base + WDTCONTROL) & ENABLE_MASK) == >>> + ENABLE_MASK) >>> + return true; >>> + else >>> + return false; >> >> return !!(readl_relaxed(wdt->base + WDTCONTROL) & ENABLE_MASK)); >> > > Note ENABLE_MASK contains two bits (INT_ENABLE and RESET_ENABLE); > therefore, a simple !!(expression) would not work? That is, the masked > result needs to be compared against the mask again to ensure both bits > are set, right? Ray - your original code looks correct to me. Easier to read and less prone to errors as shown in the attempted translation to a single statement. > > Thanks, > > Ray
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