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From: Michael Walle <michael@walle.cc>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
	devicetree <devicetree@vger.kernel.org>,
	"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
	linux-hwmon@vger.kernel.org, linux-pwm@vger.kernel.org,
	linux-watchdog@vger.kernel.org,
	"linux-arm Mailing List" <linux-arm-kernel@lists.infradead.org>,
	"Linus Walleij" <linus.walleij@linaro.org>,
	"Bartosz Golaszewski" <bgolaszewski@baylibre.com>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Jean Delvare" <jdelvare@suse.com>,
	"Guenter Roeck" <linux@roeck-us.net>,
	"Lee Jones" <lee.jones@linaro.org>,
	"Thierry Reding" <thierry.reding@gmail.com>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	"Wim Van Sebroeck" <wim@linux-watchdog.org>,
	"Shawn Guo" <shawnguo@kernel.org>, "Li Yang" <leoyang.li@nxp.com>,
	"Thomas Gleixner" <tglx@linutronix.de>,
	"Jason Cooper" <jason@lakedaemon.net>,
	"Marc Zyngier" <maz@kernel.org>,
	"Mark Brown" <broonie@kernel.org>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Andy Shevchenko" <andriy.shevchenko@linux.intel.com>
Subject: Re: [PATCH v4 04/11] watchdog: add support for sl28cpld watchdog
Date: Fri, 05 Jun 2020 12:24:54 +0200
Message-ID: <8f042c2442852c29519c381833f3d289@walle.cc> (raw)
In-Reply-To: <CAHp75VdeD6zDc--R4NPHsiqQerzfNGwUikLN+WHMiZZVsQ8QSA@mail.gmail.com>

Am 2020-06-05 10:14, schrieb Andy Shevchenko:
> On Fri, Jun 5, 2020 at 12:14 AM Michael Walle <michael@walle.cc> wrote:
>> 
>> Add support for the watchdog of the sl28cpld board management
>> controller. This is part of a multi-function device driver.
> 
> ...
> 
>> +#include <linux/of_device.h>
> 
> Didn't find a user of this.

I guess mod_devicetable.h then.

> 
> ...
> 
>> +static bool nowayout = WATCHDOG_NOWAYOUT;
>> +module_param(nowayout, bool, 0);
>> +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started 
>> (default="
>> +                               __MODULE_STRING(WATCHDOG_NOWAYOUT) 
>> ")");
>> +
>> +static int timeout;
>> +module_param(timeout, int, 0);
>> +MODULE_PARM_DESC(timeout, "Initial watchdog timeout in seconds");
> 
> Guenter ACKed this, but I'm wondering why we still need module 
> parameters...

How would a user change the nowayout or the timeout? For the latter 
there is
a device tree entry, but thats not easy changable by the user.

> 
> ...
> 
>> +       int ret;
>> +
>> +       ret = regmap_read(wdt->regmap, wdt->offset + WDT_COUNT, &val);
>> +
>> +       return (ret < 0) ? 0 : val;
> 
> Besides extra parentheses and questionable ' < 0' part, the following
> would look better I think
> 
> ret = ...
> if (ret)
>   return 0;
> 
> return val;

yes, you're right.

> 
> ...
> 
>> +       int ret;
>> +
>> +       ret = regmap_write(wdt->regmap, wdt->offset + WDT_TIMEOUT, 
>> timeout);
>> +       if (!ret)
>> +               wdd->timeout = timeout;
>> +
>> +       return ret;
> 
> Similar story here:
> 
> ret = ...
> if (ret)
>   return ret;
> 
> wdd->... = ...
> return 0;
> 
> ...

ok

> 
>> +       ret = regmap_read(wdt->regmap, wdt->offset + WDT_CTRL, 
>> &status);
> 
>> +       if (ret < 0)
> 
> What ' < 0' means? Do we have some positive return values?
> Ditto for all your code.

probably not, I'll go over all return values and change them.

>> +               return ret;
> 
> ...
> 
>> +       if (status & WDT_CTRL_EN) {
>> +               sl28cpld_wdt_start(wdd);
> 
>> +               set_bit(WDOG_HW_RUNNING, &wdd->status);
> 
> Do you need atomic op here? Why?

I'd say consistency, all watchdog drivers do it like that. I just
had a look at where this is used, but it looks like access from
userspace is protected by a lock.

> 
>> +       }
> 
> ...
> 
>> +static const struct of_device_id sl28cpld_wdt_of_match[] = {
>> +       { .compatible = "kontron,sl28cpld-wdt" },
> 
>> +       {},
> 
> No comma.

yeah ;)

-- 
-michael

  reply index

Thread overview: 74+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-04 21:10 [PATCH v4 00/11] Add support for Kontron sl28cpld Michael Walle
2020-06-04 21:10 ` [PATCH v4 01/11] dt-bindings: mfd: Add bindings for sl28cpld Michael Walle
2020-06-09 16:28   ` Rob Herring
2020-06-04 21:10 ` [PATCH v4 02/11] mfd: Add support for Kontron sl28cpld management controller Michael Walle
2020-06-05  6:57   ` Lee Jones
2020-06-05  9:51     ` Michael Walle
2020-06-05 10:50     ` Mark Brown
2020-06-05 20:07       ` Michael Walle
2020-06-06 11:46         ` Mark Brown
2020-06-06 12:45           ` Michael Walle
2020-06-08  8:28             ` Lee Jones
2020-06-08 10:02               ` Andy Shevchenko
2020-06-08 15:41                 ` Michael Walle
2020-06-08 18:56                   ` Lee Jones
2020-06-08 21:09                     ` Michael Walle
2020-06-09  6:47                       ` Lee Jones
2020-06-09 14:38                         ` Michael Walle
2020-06-09 14:42                           ` Mark Brown
2020-06-09 15:01                             ` Michael Walle
2020-06-09 17:15                               ` Rob Herring
2020-06-09 17:29                                 ` Mark Brown
2020-06-09 18:41                                 ` Lee Jones
2020-06-09 15:19                           ` Lee Jones
2020-06-09 15:30                             ` Michael Walle
2020-06-09 19:45                               ` Lee Jones
2020-06-10  7:10                                 ` Michael Walle
2020-06-10  7:19                                   ` Lee Jones
2020-06-10  7:49                                     ` Michael Walle
2020-06-10  7:56                                       ` Lee Jones
2020-06-10  9:27                                         ` Michael Walle
2020-06-10 18:30                                           ` Lee Jones
2020-06-10 17:16                                     ` Rob Herring
2020-06-10 18:02                                       ` Lee Jones
2020-06-08 18:20                 ` Lee Jones
2020-06-09 16:54               ` Rob Herring
2020-06-09 18:52                 ` Lee Jones
2020-06-05  8:01   ` Andy Shevchenko
2020-06-05  8:02     ` Andy Shevchenko
2020-06-05 10:09     ` Michael Walle
2020-06-05 10:48       ` Andy Shevchenko
2020-06-05 11:51         ` Michael Walle
2020-06-04 21:10 ` [PATCH v4 03/11] irqchip: add sl28cpld interrupt controller support Michael Walle
2020-06-05  1:26   ` kernel test robot
2020-06-05  8:07   ` Andy Shevchenko
2020-06-08 15:12   ` kernel test robot
2020-06-04 21:10 ` [PATCH v4 04/11] watchdog: add support for sl28cpld watchdog Michael Walle
2020-06-05  8:14   ` Andy Shevchenko
2020-06-05 10:24     ` Michael Walle [this message]
2020-06-05 10:50       ` Andy Shevchenko
2020-06-05 13:52         ` Guenter Roeck
2020-06-05 14:09           ` Andy Shevchenko
2020-06-05 15:05             ` Guenter Roeck
2020-06-05 16:04               ` Andy Shevchenko
2020-06-05 16:34                 ` Guenter Roeck
2020-06-04 21:10 ` [PATCH v4 05/11] pwm: add support for sl28cpld PWM controller Michael Walle
2020-06-05  8:15   ` Andy Shevchenko
2020-06-05  8:49   ` Lee Jones
2020-06-05  9:33     ` Andy Shevchenko
2020-06-05 11:39     ` Michael Walle
2020-06-05 18:17     ` Michael Walle
2020-06-08  7:46       ` Lee Jones
2020-06-04 21:10 ` [PATCH v4 06/11] gpio: add support for the sl28cpld GPIO controller Michael Walle
2020-06-05 12:00   ` Andy Shevchenko
2020-06-05 12:42     ` Michael Walle
2020-06-05 13:15       ` Andy Shevchenko
2020-06-05 18:44         ` Michael Walle
2020-06-05 21:19           ` Andy Shevchenko
2020-06-04 21:10 ` [PATCH v4 07/11] hwmon: add support for the sl28cpld hardware monitoring controller Michael Walle
2020-06-05 12:06   ` Andy Shevchenko
2020-06-04 21:10 ` [PATCH v4 08/11] arm64: dts: freescale: sl28: enable sl28cpld Michael Walle
2020-06-04 21:10 ` [PATCH v4 09/11] arm64: dts: freescale: sl28: map GPIOs to input events Michael Walle
2020-06-04 21:10 ` [PATCH v4 10/11] arm64: dts: freescale: sl28: enable LED support Michael Walle
2020-06-04 21:10 ` [PATCH v4 11/11] arm64: dts: freescale: sl28: enable fan support Michael Walle
2020-06-05  6:13 ` [PATCH v4 00/11] Add support for Kontron sl28cpld Lee Jones

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