From: Arnd Bergmann <arnd@arndb.de>
To: Rob Herring <robherring2@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Jeremy Kerr <jeremy.kerr@au1.ibm.com>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Olof Johansson <olof@lixom.net>,
Grant Likely <grant.likely@linaro.org>,
Greg KH <gregkh@linuxfoundation.org>
Subject: Re: [PATCH] drivers/core/of: Add symlink to device-tree from devices with an OF node
Date: Wed, 19 Nov 2014 15:49:13 +0100 [thread overview]
Message-ID: <11269246.iBzpsM0jDI@wuerfel> (raw)
In-Reply-To: <CAL_JsqKk5UdFEa02wA+3N5BCM7coWAK=4jAr96Pw5eFh2n0ioQ@mail.gmail.com>
On Wednesday 19 November 2014 08:45:58 Rob Herring wrote:
> > static inline struct device_node *dev_of_node(struct device *of_node)
> > {
> > if (!IS_ENABLED(CONFIG_OF))
> > return NULL;
> >
> > return dev->of_node;
> > }
> >
> > Adding the IS_ENABLED() in a lot of drivers isn't horrible, but we seem
> > to be doing it a lot.
>
> I think you misread things. of_node is always present now, so it
> should always be NULL for !CONFIG_OF.
>
No, I didn't misread it but I should have been clearer with the intention:
The idea is to tell the compiler that we know it will be NULL when CONFIG_OF
is unset, so it can optimize out all code that does
struct device_node *dn = dev_of_node(dev);
if (dn) {
...
/* complex code */
...
}
and we can avoid using an #ifdef or if(IS_ENABLED()) in the source to
compile out the DT-only sections of a driver.
Arnd
next prev parent reply other threads:[~2014-11-19 14:49 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-07 6:33 [RFC] Add of_path property for all devices with a node Benjamin Herrenschmidt
2014-11-07 6:35 ` Benjamin Herrenschmidt
2014-11-10 5:17 ` Benjamin Herrenschmidt
2014-11-10 14:06 ` Rob Herring
2014-11-10 22:48 ` Benjamin Herrenschmidt
2014-11-13 1:10 ` [PATCH] drivers/core/of: Add symlink to device-tree from devices with an OF node Benjamin Herrenschmidt
2014-11-18 16:37 ` Rob Herring
2014-11-18 23:39 ` Jeremy Kerr
2014-11-18 23:53 ` Jeremy Kerr
2014-11-19 2:35 ` Benjamin Herrenschmidt
2014-11-19 8:38 ` Arnd Bergmann
2014-11-19 14:45 ` Rob Herring
2014-11-19 14:49 ` Arnd Bergmann [this message]
2014-11-19 15:39 ` Rob Herring
2014-11-19 16:30 ` Grant Likely
2014-11-19 2:30 ` Benjamin Herrenschmidt
2014-11-27 3:39 ` Greg KH
2014-11-27 6:24 ` Benjamin Herrenschmidt
2014-11-18 15:18 ` [RFC] Add of_path property for all devices with a node Grant Likely
2014-11-19 2:25 ` Benjamin Herrenschmidt
2015-02-18 0:25 ` [PATCH 2/2 v3] drivers/core/of: Add symlink to device-tree from devices with an OF node Benjamin Herrenschmidt
2015-02-18 1:07 ` Rob Herring
2015-02-18 4:57 ` Greg Kroah-Hartman
2015-02-18 9:50 ` Benjamin Herrenschmidt
2015-03-10 14:22 ` Rob Herring
2015-03-10 15:11 ` Greg Kroah-Hartman
2015-02-18 4:57 ` Greg Kroah-Hartman
2014-11-13 4:28 ` [RFC] Add of_path property for all devices with a node Frank Rowand
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