From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932100AbeEWHwf (ORCPT ); Wed, 23 May 2018 03:52:35 -0400 Received: from mail-qt0-f195.google.com ([209.85.216.195]:44144 "EHLO mail-qt0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753992AbeEWHwc (ORCPT ); Wed, 23 May 2018 03:52:32 -0400 X-Google-Smtp-Source: AB8JxZrEH09EetAC9VGS7Tiek9Cdl4OD8idMGeCD7XH3L0qpCoi3TDBf7bsy9lK94XyfRAziUepf7g== Subject: Re: [PATCH 3/5] watchdog: sp805: set WDOG_HW_RUNNING when appropriate To: Ray Jui , Guenter Roeck Cc: Wim Van Sebroeck , Rob Herring , Mark Rutland , Frank Rowand , Catalin Marinas , Will Deacon , linux-watchdog@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com References: <1527014840-21236-1-git-send-email-ray.jui@broadcom.com> <1527014840-21236-4-git-send-email-ray.jui@broadcom.com> <20180522205457.GA16363@roeck-us.net> <0d92b9e9-a3d1-6e91-8371-b5ed3a83e399@broadcom.com> From: Scott Branden Message-ID: <00c121ea-d197-93b8-2f56-bcca963f70fb@broadcom.com> Date: Wed, 23 May 2018 00:52:27 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <0d92b9e9-a3d1-6e91-8371-b5ed3a83e399@broadcom.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 >>> Reviewed-by: Vladimir Olovyannikov >>> Reviewed-by: Scott Branden >>> --- >>>   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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: scott.branden@broadcom.com (Scott Branden) Date: Wed, 23 May 2018 00:52:27 -0700 Subject: [PATCH 3/5] watchdog: sp805: set WDOG_HW_RUNNING when appropriate In-Reply-To: <0d92b9e9-a3d1-6e91-8371-b5ed3a83e399@broadcom.com> References: <1527014840-21236-1-git-send-email-ray.jui@broadcom.com> <1527014840-21236-4-git-send-email-ray.jui@broadcom.com> <20180522205457.GA16363@roeck-us.net> <0d92b9e9-a3d1-6e91-8371-b5ed3a83e399@broadcom.com> Message-ID: <00c121ea-d197-93b8-2f56-bcca963f70fb@broadcom.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 >>> Reviewed-by: Vladimir Olovyannikov >>> Reviewed-by: Scott Branden >>> --- >>> ? 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