linux-kernel - Re: [PATCH 1/2] gpio / ACPI: Avoid unnecessary checks in __gpiod_get

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]

Message-ID: <20150311084324.GD1563@lahna.fi.intel.com>
Date:	Wed, 11 Mar 2015 10:43:24 +0200
From:	Mika Westerberg <mika.westerberg@...ux.intel.com>
To:	"Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:	Linus Walleij <linus.walleij@...aro.org>,
	Alexandre Courbot <gnurou@...il.com>,
	linux-gpio@...r.kernel.org,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	ACPI Devel Maling List <linux-acpi@...r.kernel.org>
Subject: Re: [PATCH 1/2] gpio / ACPI: Avoid unnecessary checks in
 __gpiod_get_index()

On Tue, Mar 10, 2015 at 11:08:57PM +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> 
> If dev is NULL in __gpiod_get_index() and both ACPI and OF are
> enabled, it will be checked twice before the code decides to give
> up with DT/ACPI lookup, so avoid that.
> 
> Also use the observation that ACPI_COMPANION() is much more efficient
> than ACPI_HANDLE(), because the latter uses the former and carries out
> a check and a pointer dereference on top of it, so replace the
> ACPI_HANDLE() check with an ACPI_COMPANION() one which does not
> require the additional IS_ENABLED(CONFIG_ACPI) check too.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

Acked-by: Mika Westerberg <mika.westerberg@...ux.intel.com>
--
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/