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From: Peter Chen <hzpeterchen-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
To: Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
Cc: Peter Chen <peter.chen-KZfg59tc24xl57MIdRCFDg@public.gmane.org>,
	gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org,
	stern-nwvwT67g6+6dFdvTe/nMLpVzexx5G7lz@public.gmane.org,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
	pawel.moll-5wv7dgnIgG8@public.gmane.org,
	mark.rutland-5wv7dgnIgG8@public.gmane.org,
	linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	balbi-l0cyMroinI0@public.gmane.org,
	valentin.longchamp-SkAbAL50j+5BDgjK7y7TUQ@public.gmane.org
Subject: Re: [RFC PATCH 2/2] usb: Example for how to use device node at usb device driver
Date: Sat, 9 Jan 2016 16:57:56 +0800	[thread overview]
Message-ID: <20160109085756.GC27759@shlinux2> (raw)
In-Reply-To: <4231421.FQCAATyWeB@wuerfel>

On Fri, Jan 08, 2016 at 09:26:10AM +0100, Arnd Bergmann wrote:
> On Friday 08 January 2016 13:44:24 Peter Chen wrote:
> > +	  u32 duration_us = 0;
> 
> > +       of_property_read_u32(hdev->dev.of_node, "delay-duration-us", &duration_us);
> > +       if (duration_us > 0) {
> > +               usleep_range(duration_us, duration_us + 10);
> > +               dev_info(&hdev->dev, "The delay is %d us\n", duration_us);
> > +       }
> > +
> 
> I think especially for an example, it would be better to use error checking and
> not initialize the variable:
> 
> 	u32 duration_us;
> 	int ret;
> ...
> 	ret = of_property_read_u32(hdev->dev.of_node, "delay-duration-us", &duration_us);
> 	if (!ret && duration_us > 0) {
> 		...
> 	}
> 
> The effect is the same as the other one.
> 

Thanks, will change.

-- 

Best Regards,
Peter Chen
--
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WARNING: multiple messages have this Message-ID (diff)
From: hzpeterchen@gmail.com (Peter Chen)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH 2/2] usb: Example for how to use device node at usb device driver
Date: Sat, 9 Jan 2016 16:57:56 +0800	[thread overview]
Message-ID: <20160109085756.GC27759@shlinux2> (raw)
In-Reply-To: <4231421.FQCAATyWeB@wuerfel>

On Fri, Jan 08, 2016 at 09:26:10AM +0100, Arnd Bergmann wrote:
> On Friday 08 January 2016 13:44:24 Peter Chen wrote:
> > +	  u32 duration_us = 0;
> 
> > +       of_property_read_u32(hdev->dev.of_node, "delay-duration-us", &duration_us);
> > +       if (duration_us > 0) {
> > +               usleep_range(duration_us, duration_us + 10);
> > +               dev_info(&hdev->dev, "The delay is %d us\n", duration_us);
> > +       }
> > +
> 
> I think especially for an example, it would be better to use error checking and
> not initialize the variable:
> 
> 	u32 duration_us;
> 	int ret;
> ...
> 	ret = of_property_read_u32(hdev->dev.of_node, "delay-duration-us", &duration_us);
> 	if (!ret && duration_us > 0) {
> 		...
> 	}
> 
> The effect is the same as the other one.
> 

Thanks, will change.

-- 

Best Regards,
Peter Chen

  reply	other threads:[~2016-01-09  8:57 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-08  5:44 [RFC PATCH 0/2] USB: let the USB device know device node Peter Chen
2016-01-08  5:44 ` Peter Chen
     [not found] ` <1452231864-11171-1-git-send-email-peter.chen-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
2016-01-08  5:44   ` [RFC PATCH 1/2] USB: core: let " Peter Chen
2016-01-08  5:44     ` Peter Chen
     [not found]     ` <1452231864-11171-2-git-send-email-peter.chen-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
2016-01-08  8:22       ` Arnd Bergmann
2016-01-08  8:22         ` Arnd Bergmann
2016-01-09  8:56         ` Peter Chen
2016-01-09  8:56           ` Peter Chen
2016-01-08 14:32       ` Rob Herring
2016-01-08 14:32         ` Rob Herring
     [not found]         ` <CAL_JsqKwATxGiqJ_MNV6_pur1dUEVOzH+iB8yY+kWA0y2gWbNg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-01-09  9:05           ` Peter Chen
2016-01-09  9:05             ` Peter Chen
2016-01-09 15:20             ` Rob Herring
2016-01-09 15:20               ` Rob Herring
2016-01-08 22:50       ` Alan Stern
2016-01-08 22:50         ` Alan Stern
     [not found]         ` <Pine.LNX.4.44L0.1601081746080.21467-100000-pYrvlCTfrz9XsRXLowluHWD2FQJk+8+b@public.gmane.org>
2016-01-09  9:32           ` Peter Chen
2016-01-09  9:32             ` Peter Chen
2016-01-08  5:44   ` [RFC PATCH 2/2] usb: Example for how to use device node at usb device driver Peter Chen
2016-01-08  5:44     ` Peter Chen
     [not found]     ` <1452231864-11171-3-git-send-email-peter.chen-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
2016-01-08  8:26       ` Arnd Bergmann
2016-01-08  8:26         ` Arnd Bergmann
2016-01-09  8:57         ` Peter Chen [this message]
2016-01-09  8:57           ` Peter Chen

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