linux-kernel - Re: [PATCH RFC v2 2/2] pinctrl: add pinctrl gpio binding support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 21 May 2012 11:11:25 -0600
From:	Stephen Warren <swarren@...dotorg.org>
To:	Dong Aisheng <aisheng.dong@...escale.com>
CC:	Dong Aisheng-B29396 <B29396@...escale.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linus.walleij@...ricsson.com" <linus.walleij@...ricsson.com>
Subject: Re: [PATCH RFC v2 2/2] pinctrl: add pinctrl gpio binding support

On 05/21/2012 06:39 AM, Dong Aisheng wrote:
> On Sat, May 19, 2012 at 04:05:46AM +0800, Stephen Warren wrote:
>> On 05/18/2012 07:12 AM, Dong Aisheng wrote:
>>> The gpio ranges standard dt binding format is
>>> <&gpio $gpio_offset $pin_offset $npin>
>>>
>>> The core will parse and register the pinctrl gpio ranges
>>> from device tree.
...
>> Do you need to xxx_get(ranges[i].gc) to prevent it going away, and put()
>> it when removing the ranges?
>
> How would you suggest to implement xxx_get(ranges[i].gc)?
> Since the parameter is a struct gpiochip, my first sense is that it may be
> provided by gpio subsystem, but i did not find such a function.
> Looking at gpio subsystem, i also can't see it should provide such function.
> 
> I wonder if we need to implement it, if gpiochip is gone way,
> the error will be detected in the higher gpio layer and will not pass
> down to pinctrl.

Yes, it looks like we should add new APIs for this; we need to
try_module_get() on the module containing the GPIO chip so it doesn't
disappear, similar to what gpio_request() does.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/