From: Johan Hovold <johan@kernel.org>
To: Mark Brown <broonie@kernel.org>
Cc: Johan Hovold <johan@kernel.org>,
Linus Walleij <linus.walleij@linaro.org>,
linux-gpio@vger.kernel.org,
Alexandre Courbot <acourbot@nvidia.com>,
Arnd Bergmann <arnd@arndb.de>,
Michael Welling <mwelling@ieee.org>,
Markus Pargmann <mpa@pengutronix.de>,
Amit Kucheria <amit.kucheria@linaro.org>
Subject: Re: [PATCH 1/6] gpio: make the gpiochip a real device
Date: Mon, 2 Nov 2015 13:53:47 +0100 [thread overview]
Message-ID: <20151102125347.GA12752@localhost> (raw)
In-Reply-To: <20151102124737.GG20228@sirena.org.uk>
On Mon, Nov 02, 2015 at 12:47:37PM +0000, Mark Brown wrote:
> On Mon, Nov 02, 2015 at 01:43:23PM +0100, Johan Hovold wrote:
> > On Mon, Nov 02, 2015 at 12:25:14PM +0000, Mark Brown wrote:
>
> > > > First of all, you must never register the same device structure twice.
>
> > > Well, you can unregister and reregister (and it is reasonable practice
> > > to make sure that the struct isn't full of noise) - we usually allocate
> > > things out of kzalloc().
>
> > Actually, no. It's an explicitly forbidden practise to reregister the
> > same struct device.
>
> A memset() should be enough, if not then we have problems with any
> dynamically allocated struct device.
And how would you know that it is safe to memset that struct device?
There can still be references to it. And driver core explicitly forbids
this (see device_add() for example).
Dynamically allocated struct device are not the problem as then you're
not *reusing* the same device structure.
Johan
next prev parent reply other threads:[~2015-11-02 12:53 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-22 8:32 [PATCH 0/6] GPIO character device skeleton Linus Walleij
2015-10-22 8:32 ` [PATCH 1/6] gpio: make the gpiochip a real device Linus Walleij
2015-10-24 18:09 ` Markus Pargmann
2015-10-25 7:06 ` Alexandre Courbot
2015-10-26 2:12 ` Mark Brown
2015-11-03 21:20 ` Linus Walleij
2015-11-02 10:31 ` Johan Hovold
2015-11-02 12:25 ` Mark Brown
2015-11-02 12:43 ` Johan Hovold
2015-11-02 12:47 ` Mark Brown
2015-11-02 12:53 ` Johan Hovold [this message]
2015-11-02 13:06 ` Mark Brown
2015-11-02 13:14 ` Johan Hovold
2015-11-02 13:17 ` Mark Brown
2015-11-02 13:25 ` Johan Hovold
2015-11-03 21:24 ` Linus Walleij
2015-11-04 10:48 ` Linus Walleij
2015-11-05 9:44 ` Johan Hovold
2015-11-05 10:29 ` Mark Brown
2015-11-16 14:27 ` Linus Walleij
2015-12-03 14:04 ` Linus Walleij
2015-12-03 14:06 ` Linus Walleij
2015-12-03 21:26 ` Michael Welling
2015-12-04 22:31 ` Michael Welling
2015-12-11 17:58 ` Linus Walleij
2015-12-08 9:29 ` Johan Hovold
2015-12-11 18:06 ` Linus Walleij
2015-10-22 8:32 ` [PATCH 2/6] gpio: refer to gpio device in prints and debugfs Linus Walleij
2015-10-22 8:32 ` [PATCH 3/6] gpio: add a userspace chardev ABI for GPIOs Linus Walleij
2015-10-22 20:35 ` Michael Welling
2015-10-24 0:30 ` Greg Kroah-Hartman
2016-01-28 11:13 ` Linus Walleij
2015-10-26 1:34 ` Mark Brown
2016-01-27 10:05 ` Bamvor Zhang Jian
2016-01-28 11:14 ` Linus Walleij
2016-01-29 10:24 ` Bamvor Zhang Jian
2016-02-10 10:04 ` Linus Walleij
2015-10-22 8:32 ` [PATCH 4/6] tools/gpio: create GPIO tools Linus Walleij
2015-10-25 8:23 ` Alexandre Courbot
2015-10-22 8:32 ` [PATCH 5/6] gpio: add a userspace character device ABI Linus Walleij
2015-10-24 18:46 ` Markus Pargmann
2015-10-22 8:32 ` [PATCH 6/6] gpio: ABI: mark the sysfs ABI as obsolete Linus Walleij
2015-10-22 18:57 ` [PATCH 0/6] GPIO character device skeleton Michael Welling
2015-10-24 17:53 ` Markus Pargmann
2015-10-30 14:40 ` Linus Walleij
2015-11-02 10:00 ` Johan Hovold
2015-10-24 18:42 ` Markus Pargmann
2015-10-30 1:55 ` Alexandre Courbot
2015-10-30 19:48 ` Linus Walleij
2015-11-02 10:13 ` Johan Hovold
2015-11-03 7:23 ` Markus Pargmann
2015-11-03 12:06 ` Johan Hovold
2015-11-03 17:18 ` Linus Walleij
2015-11-04 19:44 ` Michael Welling
2015-11-05 9:40 ` Johan Hovold
2015-11-05 14:11 ` Linus Walleij
2015-11-06 10:21 ` Johan Hovold
2015-11-16 13:33 ` Linus Walleij
2015-11-03 17:05 ` Linus Walleij
2015-10-30 14:43 ` Linus Walleij
2015-10-30 22:54 ` Arnd Bergmann
2015-11-01 9:37 ` Linus Walleij
2015-11-02 10:16 ` Johan Hovold
2015-10-26 2:18 ` Mark Brown
2015-10-30 1:55 ` Alexandre Courbot
2015-10-30 19:47 ` Linus Walleij
2015-11-01 2:41 ` Mark Brown
2015-11-03 7:39 ` Markus Pargmann
2015-11-03 8:50 ` Mark Brown
2015-11-03 10:21 ` Amit Kucheria
2015-11-03 17:06 ` Linus Walleij
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