From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1751695Ab1GTU1U (ORCPT <rfc822;w@1wt.eu>);
	Wed, 20 Jul 2011 16:27:20 -0400
Received: from hqemgate04.nvidia.com ([216.228.121.35]:7001 "EHLO
	hqemgate04.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1751227Ab1GTU1S convert rfc822-to-8bit (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Wed, 20 Jul 2011 16:27:18 -0400
X-PGP-Universal: processed;
	by hqnvupgp06.nvidia.com on Wed, 20 Jul 2011 13:27:10 -0700
From: Andrew Chew <AChew@nvidia.com>
To: "'Grant Likely'" <grant.likely@secretlab.ca>
CC: "olof@lixom.net" <olof@lixom.net>, Stephen Warren <swarren@nvidia.com>,
        Dan Willemsen <dwillemsen@nvidia.com>,
        Rhyland Klein <rklein@nvidia.com>,
        Venkat Moganty <vmoganty@nvidia.com>,
        "devicetree-discuss@lists.ozlabs.org" 
	<devicetree-discuss@lists.ozlabs.org>,
        "linux-tegra@vger.kernel.org" <linux-tegra@vger.kernel.org>,
        "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Date: Wed, 20 Jul 2011 13:27:10 -0700
Subject: RE: [PATCH 1/3 v2] usb: tegra20-ehci: Add devicetree support.
Thread-Topic: [PATCH 1/3 v2] usb: tegra20-ehci: Add devicetree support.
Thread-Index: AcxHGlnS5fVWPwrKRe2c+HXs3z1rZwAAJGKw
Message-ID: <643E69AA4436674C8F39DCC2C05F76383CF0DD2278@HQMAIL03.nvidia.com>
References: <1311190690-18334-1-git-send-email-achew@nvidia.com>
 <CACxGe6uDVdemjbjY_i-_M_-VT8HuLdtXP-R9V8kB+pSSin4dEw@mail.gmail.com>
 <643E69AA4436674C8F39DCC2C05F76383CF0DD2277@HQMAIL03.nvidia.com>
 <CACxGe6tEEr11vd3tqDwQ00YhUi7tMzovmS2PZGW9jt1K6VBefg@mail.gmail.com>
In-Reply-To: <CACxGe6tEEr11vd3tqDwQ00YhUi7tMzovmS2PZGW9jt1K6VBefg@mail.gmail.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach: 
X-MS-TNEF-Correlator: 
acceptlanguage: en-US
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: 8BIT
MIME-Version: 1.0
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

> >> Can the driver use sane defaults for any of these values?  
> This patch
> >> will be a lot smaller if there isn't the need to check all 
> the return
> >> values each time.
> >
> > The defaults are in the dt ehci node.  I'd really hate to 
> duplicate these defaults in C code as well, if that's what 
> you're suggesting (they're already duplicated privately 
> elsewhere, sadly, in mach-tegra, but I'm hoping those 
> defaults can go away once we move over to dt for good).  By 
> failing probe if these defaults aren't present, I think it 
> helps make sure the dt ehci node stays in sync with the code.
> 
> I'm saying that if the binding and the driver encode sane defaults for
> those parameters, then the properties don't need to appear in the .dts
> at all unless they are being overridden.  It is by no means a critical
> issue though.  Do what makes the most sense to you.

I see.  I think that makes sense as well.  To be clear, you're suggesting to document the defaults in the bindings file, and have the defaults in the driver (C code).  Then omit the properties from the dts entirely unless they are different (i.e. the dts will no longer have any default values specified), right?  If that's more consistent with how the other drivers will work, I'll do that.