Messages in this thread | | | Subject | Re: [PATCH 3/5] watchdog: sp805: set WDOG_HW_RUNNING when appropriate | From | Robin Murphy <> | Date | Wed, 23 May 2018 12:48:10 +0100 |
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On 23/05/18 08:52, Scott Branden wrote: > > > 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.
if (<boolean condition>) return true; else return false;
still looks really dumb, though, and IMO is actually harder to read than just "return <boolean condition>;" because it forces you to stop and double-check that the logic is, in fact, only doing the obvious thing.
Robin.
p.s. No thanks for making me remember the mind-boggling horror of briefly maintaining part of this legacy codebase... :P
$ grep -r '? true : false' --include=*.cpp . | wc -l 951
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