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

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Message-ID: <CACRpkdaZvdQSvD4a3xG_uLdZGG3ZPSh_70WEUe6ZA8RTPYVb6Q@mail.gmail.com>
Date:	Wed, 18 Mar 2015 02:33:31 +0100
From:	Linus Walleij <linus.walleij@...aro.org>
To:	"Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:	Alexandre Courbot <gnurou@...il.com>,
	"linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	ACPI Devel Maling List <linux-acpi@...r.kernel.org>,
	Mika Westerberg <mika.westerberg@...ux.intel.com>
Subject: Re: [PATCH 1/2] gpio / ACPI: Avoid unnecessary checks in __gpiod_get_index()

On Tue, Mar 10, 2015 at 11:08 PM, Rafael J. Wysocki <rjw@...ysocki.net> 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>

Patch applied with review and ACK tags.

Yours,
Linus Walleij
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