Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932987Ab2JWPJZ (ORCPT ); Tue, 23 Oct 2012 11:09:25 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:53228 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755437Ab2JWPJY (ORCPT ); Tue, 23 Oct 2012 11:09:24 -0400 Message-ID: <5086B316.6000001@ti.com> Date: Tue, 23 Oct 2012 17:09:10 +0200 From: Benoit Cousson Organization: Texas Instruments User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121011 Thunderbird/16.0.1 MIME-Version: 1.0 To: Jon Hunter CC: Sebastien Guiriec , Tony Lindgren , , , Santosh Shilimkar , , Subject: Re: [PATCH v2 1/4] ARM: dts: omap5: Update GPIO with address space and interrupts References: <1350981432-6750-1-git-send-email-s-guiriec@ti.com> <1350981432-6750-2-git-send-email-s-guiriec@ti.com> <5086AE8E.60106@ti.com> In-Reply-To: <5086AE8E.60106@ti.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2036 Lines: 55 On 10/23/2012 04:49 PM, Jon Hunter wrote: > Hi Seb, > > On 10/23/2012 03:37 AM, Sebastien Guiriec wrote: >> Add base address and interrupt line inside Device Tree data for >> OMAP5 >> >> Signed-off-by: Sebastien Guiriec >> --- >> arch/arm/boot/dts/omap5.dtsi | 16 ++++++++++++++++ >> 1 file changed, 16 insertions(+) >> >> diff --git a/arch/arm/boot/dts/omap5.dtsi b/arch/arm/boot/dts/omap5.dtsi >> index 42c78be..9e39f9f 100644 >> --- a/arch/arm/boot/dts/omap5.dtsi >> +++ b/arch/arm/boot/dts/omap5.dtsi >> @@ -104,6 +104,8 @@ >> >> gpio1: gpio@4ae10000 { >> compatible = "ti,omap4-gpio"; >> + reg = <0x4ae10000 0x200>; >> + interrupts = <0 29 0x4>; >> ti,hwmods = "gpio1"; >> gpio-controller; >> #gpio-cells = <2>; > > I am wondering if we should add the "interrupt-parent" property to add > nodes in the device-tree source. I know that today the interrupt-parent > is being defined globally, but when device-tree maps an interrupt for a > device it searches for the interrupt-parent starting the current device > node. > > So in other words, for gpio1 it will search the gpio1 binding for > "interrupt-parent" and if not found move up a level and search again. It > will keep doing this until it finds the "interrupt-parent". > > Therefore, I believe it will improve search time and hence, boot time if > we have interrupt-parent defined in each node. Mmm, I'm not that sure. it will increase the size of the blob, so increase the time to load it and then to parse it. Where in the current case, it is just going up to the parent node using the already un-flatten tree in memory and thus that should not take that much time. That being said, it might be interesting to benchmark that to see what is the real impact. Regards, Benoit -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/