From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751816AbbCKBg3 (ORCPT ); Tue, 10 Mar 2015 21:36:29 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:63279 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751475AbbCKBg1 (ORCPT ); Tue, 10 Mar 2015 21:36:27 -0400 Message-ID: <54FF9C0F.3060107@huawei.com> Date: Wed, 11 Mar 2015 09:36:15 +0800 From: Hanjun Guo User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 MIME-Version: 1.0 To: "Rafael J. Wysocki" , Linus Walleij CC: Alexandre Courbot , , "Linux Kernel Mailing List" , ACPI Devel Maling List , Mika Westerberg Subject: Re: [PATCH 1/2] gpio / ACPI: Avoid unnecessary checks in __gpiod_get_index() References: <4032246.STUT1iRmIk@vostro.rjw.lan> <1829371.gDPkhnsp25@vostro.rjw.lan> In-Reply-To: <1829371.gDPkhnsp25@vostro.rjw.lan> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.17.188] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2015/3/11 6:08, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > 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 Quite straight forward to me, for both two patches, Reviewed-by: Hanjun Guo Thanks Hanjun > --- > drivers/gpio/gpiolib.c | 16 +++++++++------- > 1 file changed, 9 insertions(+), 7 deletions(-) > > Index: linux-pm/drivers/gpio/gpiolib.c > =================================================================== > --- linux-pm.orig/drivers/gpio/gpiolib.c > +++ linux-pm/drivers/gpio/gpiolib.c > @@ -1865,13 +1865,15 @@ struct gpio_desc *__must_check __gpiod_g > > dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id); > > - /* Using device tree? */ > - if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) { > - dev_dbg(dev, "using device tree for GPIO lookup\n"); > - desc = of_find_gpio(dev, con_id, idx, &lookupflags); > - } else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev)) { > - dev_dbg(dev, "using ACPI for GPIO lookup\n"); > - desc = acpi_find_gpio(dev, con_id, idx, &lookupflags); > + if (dev) { > + /* Using device tree? */ > + if (IS_ENABLED(CONFIG_OF) && dev->of_node) { > + dev_dbg(dev, "using device tree for GPIO lookup\n"); > + desc = of_find_gpio(dev, con_id, idx, &lookupflags); > + } else if (ACPI_COMPANION(dev)) { > + dev_dbg(dev, "using ACPI for GPIO lookup\n"); > + desc = acpi_find_gpio(dev, con_id, idx, &lookupflags); > + } > } > > /* > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > > . >