From: "xt.hu[胡先韬]" <xt.hu@cqplus1.com>
To: Guenter Roeck <linux@roeck-us.net>,
"wim@linux-watchdog.org" <wim@linux-watchdog.org>,
"p.zabel@pengutronix.de" <p.zabel@pengutronix.de>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-watchdog@vger.kernel.org" <linux-watchdog@vger.kernel.org>,
"robh+dt@kernel.org" <robh+dt@kernel.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>
Cc: "Wells Lu 呂芳騰" <wells.lu@sunplus.com>,
"qinjian[覃健]" <qinjian@cqplus1.com>
Subject: RE: [PATCH 1/2] watchdog: Add watchdog driver for Sunplus SP7021
Date: Wed, 24 Nov 2021 10:31:55 +0000 [thread overview]
Message-ID: <5ed3659b2cbd4227b8c2563b24bbd3be@cqplus1.com> (raw)
In-Reply-To: <1f2c5cf0-808d-92d5-487e-a3134f5d130a@roeck-us.net>
Hi, Guenter Roeck :
Thanks for your review. Sorry I was so focused on fixing code and
I forgot to respond to the email. I modify the code as you comment
and answer the question.
Thanks
Best Regards,
Xiantao Hu
> -----Original Message-----
> From: Guenter Roeck [mailto:groeck7@gmail.com] On Behalf Of Guenter Roeck
> Sent: Friday, November 12, 2021 10:46 PM
> To: xt.hu[胡先韬] <xt.hu@cqplus1.com>; wim@linux-watchdog.org; p.zabel@pengutronix.de;
> linux-kernel@vger.kernel.org; linux-watchdog@vger.kernel.org; robh+dt@kernel.org;
> devicetree@vger.kernel.org
> Cc: Wells Lu 呂芳騰 <wells.lu@sunplus.com>; qinjian[覃健] <qinjian@cqplus1.com>
> Subject: Re: [PATCH 1/2] watchdog: Add watchdog driver for Sunplus SP7021
>
> On 11/12/21 2:59 AM, Xiantao Hu wrote:
> > Sunplus SP7021 requires watchdog timer support.
> > Add watchdog driver to enable this.
> >
> > Signed-off-by: Xiantao Hu <xt.hu@cqplus1.com>
...
> > +struct sp_wdt_priv {
> > + struct watchdog_device wdev;
> > + void __iomem *base;
> > + void __iomem *miscellaneous;
>
> Please find a better name for this variable. Also, unless I am
> missing something, it is only used in the init function. That means
> it can be passed to that function as parameter and doesn't need
> to be stored in sp_wdt_priv.
>
I will remove the miscellaneous from sp_wdt_priv and pass
to that function as parameter.
> > + struct clk *clk;
> > + struct reset_control *rstc;
> > +};
...
> > +static int sp_wdt_set_timeout(struct watchdog_device *wdev,
> > + unsigned int timeout)
> > +{
> > + wdev->timeout = timeout;
> > +
>
> I would assume this also needs to set the new timeout in HW if
> the watchdog is running, or the watchdog could time out before
> userspace sends another ping.
>
I will call the ping() after assigning timeout.
> > + return 0;
> > +}
> > +
...
> > +
> > +static int sp_wdt_start(struct watchdog_device *wdev)
> > +{
> > + int ret;
> > +
> > + ret = sp_wdt_set_timeout(wdev, wdev->timeout);
>
> That function never returns an error, so checking for it is
> pointless here.
>
I will remove the variable ret.
> > + if (ret < 0)
> > + return ret;
> > +
...
> > +/*
> > + * 1.We need to reset watchdog flag(clear watchdog interrupt) here
> > + * because watchdog timer driver does not have an interrupt handler,
> > + * and before enalbe STC and RBUS watchdog timeout. Otherwise,
>
> enable
>
I will fix it.
> > + * the intr is always in the triggered state.
> > + * 2.enable STC and RBUS watchdog timeout trigger.
> > + * 3.watchdog conuter is running, need to be stopped.
>
> counter
>
I will fix it.
> > + */
...
> > +
> > + wdt_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> > + priv->miscellaneous =
> > + devm_ioremap(dev, wdt_res->start, resource_size(wdt_res));
>
> Why not use devm_ioremap_resource() ? Or, for that matter,
> devm_platform_ioremap_resource() like above ?
>
The function of this register is miscellaneous. The register
accessed here shared by multiple drivers. Use the function
of devm_platform_ioremap_resource() which internally
call request_mem_region() causes an error. So I handle it
in this way. Any better ways?
> > + if (IS_ERR(priv->miscellaneous))
> > + return PTR_ERR(priv->miscellaneous);
> > +
> > + priv->wdev.info = &sp_wdt_info;
> > + priv->wdev.ops = &sp_wdt_ops;
> > + priv->wdev.timeout = SP_WDT_MAX_TIMEOUT;
> > + priv->wdev.max_timeout = SP_WDT_MAX_TIMEOUT;
> > + priv->wdev.min_timeout = SP_WDT_MIN_TIMEOUT;
>
> THis should really use max_hw_heartbeat_ms to let the core
> ping the watchdog if larger timeouts are desired.
>
I will add the max_hw_heartbeat_ms and modify the
ping ().
> > + priv->wdev.parent = dev;
> > +
> > + watchdog_set_drvdata(&priv->wdev, priv);
> > + sp_wdt_hw_init(&priv->wdev);
> > +
> > + watchdog_init_timeout(&priv->wdev, timeout, dev);
> > + watchdog_set_nowayout(&priv->wdev, nowayout);
> > + watchdog_stop_on_reboot(&priv->wdev);
> > +
> > + err = devm_watchdog_register_device(dev, &priv->wdev);
>
> Since you call watchdog_unregister_device() below you can not use
> the devm_ function here.
>
I will drop the function remove() and not call watchdog_unregister_device() .
Use the devm_add_action_or_reset() add reset_control_assert() and
clk_disable_unprepare().
> > + if (unlikely(err))
>
> This is not time critical. Drop the unlikely.
>
I will fix it.
> > + return err;
> > +
> > + dev_info(dev, "Watchdog enabled (timeout=%d sec%s.)\n",
> > + priv->wdev.timeout, nowayout ? ", nowayout" : "");
> > +
> > + return 0;
> > +}
> > +
> > +static int sp_wdt_remove(struct platform_device *pdev)
> > +{
> > + struct sp_wdt_priv *priv = platform_get_drvdata(pdev);
> > +
> > + watchdog_unregister_device(&priv->wdev);
> > +
> > + reset_control_assert(priv->rstc);
> > + clk_disable_unprepare(priv->clk);
> > +
> > + return 0;
> > +}
> > +
...
> > +
> > +static int __maybe_unused sp_wdt_resume(struct device *dev)
> > +{
> > + struct sp_wdt_priv *priv = dev_get_drvdata(dev);
> > +
> > + if (watchdog_active(&priv->wdev))
> > + sp_wdt_start(&priv->wdev);
> > +
> Shouldn't the order be the opposite of the order in the suspend function ?
>
I will fix it.
> > + reset_control_deassert(priv->rstc);
> > + clk_prepare_enable(priv->clk);
> > +
> > + return 0;
> > +}
> >
...
> >
next prev parent reply other threads:[~2021-11-24 10:40 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-12 10:59 [PATCH 0/2] Add watchdog driver for Sunplus SP7021 SoC Xiantao Hu
2021-11-12 10:59 ` [PATCH 1/2] watchdog: Add watchdog driver for Sunplus SP7021 Xiantao Hu
2021-11-12 14:45 ` Guenter Roeck
2021-11-24 10:31 ` xt.hu[胡先韬] [this message]
2021-11-21 0:33 ` kernel test robot
2021-11-12 10:59 ` [PATCH 2/2] dt-bindings: watchdog: Add Sunplus SP7021 WDT devicetree bindings documentation Xiantao Hu
2021-11-24 10:41 ` [PATCH v2 0/2] Add watchdog driver for Sunplus SP7021 SoC Xiantao Hu
2021-11-24 10:41 ` [PATCH v2 1/2] watchdog: Add watchdog driver for Sunplus SP7021 Xiantao Hu
2021-11-24 14:25 ` Guenter Roeck
2021-11-25 2:42 ` xt.hu[胡先韬]
2021-11-25 4:25 ` Guenter Roeck
2021-11-29 7:57 ` xt.hu[胡先韬]
2021-12-03 21:39 ` Guenter Roeck
2021-11-24 10:41 ` [PATCH v2 2/2] dt-bindings: watchdog: Add Sunplus SP7021 WDT devicetree bindings documentation Xiantao Hu
2021-11-30 22:38 ` Rob Herring
2021-11-24 14:17 ` [PATCH v2 0/2] Add watchdog driver for Sunplus SP7021 SoC Guenter Roeck
2021-11-25 2:52 ` xt.hu[胡先韬]
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=5ed3659b2cbd4227b8c2563b24bbd3be@cqplus1.com \
--to=xt.hu@cqplus1.com \
--cc=devicetree@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-watchdog@vger.kernel.org \
--cc=linux@roeck-us.net \
--cc=p.zabel@pengutronix.de \
--cc=qinjian@cqplus1.com \
--cc=robh+dt@kernel.org \
--cc=wells.lu@sunplus.com \
--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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).