Linux-Watchdog Archive on lore.kernel.org
 help / color / Atom feed
From: Guenter Roeck <linux@roeck-us.net>
To: Evan Benn <evanbenn@chromium.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	"Julius Werner" <jwerner@chromium.org>,
	"Bjorn Andersson" <bjorn.andersson@linaro.org>,
	"Mauro Carvalho Chehab" <mchehab+samsung@kernel.org>,
	"Marcin Juszkiewicz" <marcin.juszkiewicz@linaro.org>,
	"Catalin Marinas" <catalin.marinas@arm.com>,
	"Olof Johansson" <olof@lixom.net>,
	"Leonard Crestez" <leonard.crestez@nxp.com>,
	"Jonathan Cameron" <Jonathan.Cameron@huawei.com>,
	"Dinh Nguyen" <dinguyen@kernel.org>,
	linux-arm-kernel@lists.infradead.org,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Will Deacon" <will@kernel.org>,
	linux-watchdog@vger.kernel.org, "Rob Herring" <robh@kernel.org>,
	"Wim Van Sebroeck" <wim@linux-watchdog.org>,
	"Clément Péron" <peron.clem@gmail.com>,
	"Shawn Guo" <shawnguo@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	"Anson Huang" <Anson.Huang@nxp.com>
Subject: Re: [PATCH 2/2] watchdog: Add new arm_smc_wdt watchdog driver
Date: Thu, 20 Feb 2020 07:52:00 -0800
Message-ID: <20200220155159.GB29658@roeck-us.net> (raw)
In-Reply-To: <CAKz_xw0fHgVBLdEoEoQ7OSAgBcvYBAowV0obWLsDUGNPotP55Q@mail.gmail.com>

On Thu, Feb 20, 2020 at 05:50:03PM +1100, Evan Benn wrote:
> > > +     if ((int)res->a0 == PSCI_RET_NOT_SUPPORTED)
> > > +             return -ENOTSUPP;
> >
> > -ENODEV would be better here.
> >
> > > +     if ((int)res->a0 == PSCI_RET_INVALID_PARAMS)
> > > +             return -EINVAL;
> > > +     if ((int)res->a0 < 0)
> > > +             return -EIO;
> 
> In fixing this I found drivers/firmware/psci/psci.c:145
> Which also translates psci codes to errno codes, but uses EOPNOTSUPP:
> 
>     switch (errno) {
>     case PSCI_RET_SUCCESS:
>         return 0;
>     case PSCI_RET_NOT_SUPPORTED:
>         return -EOPNOTSUPP;
>     case PSCI_RET_INVALID_PARAMS:
>     case PSCI_RET_INVALID_ADDRESS:
>         return -EINVAL;
>     case PSCI_RET_DENIED:
>         return -EPERM;
>     };
> 
>     return -EINVAL;
> 
> Are these more appropriate?
> 

It is customary for driver probe functions to return -ENODEV if the
device is not supported. I don't see a reason why this driver should
behave any different. "but this other driver does it" is never a good
argument.

Having said that, yet, with the exception of -EOPNOTSUPP the other
return values would be more appropriate.

Guenter

      reply index

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-14  6:26 [PATCH 0/2] Add a watchdog driver that uses ARM Secure Monitor Calls Evan Benn
2020-02-14  6:26 ` [PATCH 1/2] dt-bindings: watchdog: Add arm,smc-wdt watchdog arm,smc-wdt compatible Evan Benn
2020-02-19 22:30   ` Rob Herring
2020-02-19 23:04     ` Julius Werner
2020-02-19 23:20       ` Guenter Roeck
2020-02-20  6:41         ` Evan Benn
2020-02-20 15:43           ` Guenter Roeck
2020-02-21 15:36           ` Xingyu Chen
2020-02-21 19:41             ` Julius Werner
2020-02-21 20:46               ` Guenter Roeck
2020-02-22  4:01               ` Xingyu Chen
2020-02-24  1:10                 ` Evan Benn
2020-02-25  1:23                 ` Julius Werner
2020-02-25  7:44                   ` Xingyu Chen
2020-03-10  1:00                     ` Evan Benn
     [not found]                       ` <ad28aa47-0490-937f-898f-0e4695ef6ec6@amlogic.com>
2020-03-11 19:24                         ` Julius Werner
2020-03-13 16:13                           ` Xingyu Chen
2020-02-14  6:26 ` [PATCH 2/2] watchdog: Add new arm_smc_wdt watchdog driver Evan Benn
2020-02-14  9:35   ` Enric Balletbo Serra
2020-02-14 14:10   ` Guenter Roeck
2020-02-14 21:32     ` Julius Werner
2020-02-15  1:39       ` Evan Benn
2020-02-20  6:50     ` Evan Benn
2020-02-20 15:52       ` Guenter Roeck [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200220155159.GB29658@roeck-us.net \
    --to=linux@roeck-us.net \
    --cc=Anson.Huang@nxp.com \
    --cc=Jonathan.Cameron@huawei.com \
    --cc=bjorn.andersson@linaro.org \
    --cc=catalin.marinas@arm.com \
    --cc=davem@davemloft.net \
    --cc=dinguyen@kernel.org \
    --cc=evanbenn@chromium.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=jwerner@chromium.org \
    --cc=leonard.crestez@nxp.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-watchdog@vger.kernel.org \
    --cc=marcin.juszkiewicz@linaro.org \
    --cc=mchehab+samsung@kernel.org \
    --cc=olof@lixom.net \
    --cc=peron.clem@gmail.com \
    --cc=robh@kernel.org \
    --cc=shawnguo@kernel.org \
    --cc=will@kernel.org \
    --cc=wim@linux-watchdog.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Watchdog Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-watchdog/0 linux-watchdog/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-watchdog linux-watchdog/ https://lore.kernel.org/linux-watchdog \
		linux-watchdog@vger.kernel.org
	public-inbox-index linux-watchdog

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-watchdog


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git