From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757096AbbAINd5 (ORCPT ); Fri, 9 Jan 2015 08:33:57 -0500 Received: from mail-we0-f169.google.com ([74.125.82.169]:34305 "EHLO mail-we0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752146AbbAINdz (ORCPT ); Fri, 9 Jan 2015 08:33:55 -0500 Date: Fri, 9 Jan 2015 14:33:51 +0100 From: Thierry Reding To: Daniel Lezcano Cc: Paul Walmsley , linux-kernel@vger.kernel.org, Thomas Gleixner , linux-tegra@vger.kernel.org, Allen Martin , Stephen Warren , Thierry Reding , Alexandre Courbot , pwalmsley@nvidia.com Subject: Re: [PATCH] clocksource: tegra: wrap arch/arm-specific sections in CONFIG_ARM Message-ID: <20150109133349.GA27876@ulmo> References: <54AEB719.5060103@linaro.org> <54AF91CC.2090007@linaro.org> <20150109122120.GJ16465@ulmo> <54AFD688.5000304@linaro.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="9amGYk9869ThD9tj" Content-Disposition: inline In-Reply-To: <54AFD688.5000304@linaro.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --9amGYk9869ThD9tj Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Jan 09, 2015 at 02:24:24PM +0100, Daniel Lezcano wrote: > On 01/09/2015 01:21 PM, Thierry Reding wrote: > >On Fri, Jan 09, 2015 at 09:31:08AM +0100, Daniel Lezcano wrote: > >>On 01/09/2015 03:09 AM, Paul Walmsley wrote: > >>>Hello Daniel > >>> > >>>On Thu, 8 Jan 2015, Daniel Lezcano wrote: > >>> > >>>>On 12/09/2014 11:07 PM, Paul Walmsley wrote: > >>>>> > >>>>>Like several of the other files in drivers/clocksource, > >>>>>tegra20_timer.c contains code that can only compile when CONFIG_ARM = is > >>>>>enabled. This causes obvious problems when trying to compile this > >>>>>code for NVIDIA ARM64-based SoCs, such as Tegra132. The same timer = IP > >>>>>blocks exist, so it seems appropriate to provide support for them. > >>>>> > >>>>>So until we figure out a better way to partition this code, wrap the > >>>>>delay_timer and persistent_clock support code with preprocessor tests > >>>>>for CONFIG_ARM. > >>>>> > >>>>> (The delay_timer code should not be needed at all on > >>>>>ARM64 due to the presence of the ARMv8 architected timer. The > >>>>>persistent_clock support code could become important once power > >>>>>management modes are implemented that turn off the CPU complex.) > >>>> > >>>>IIUC, the cpuidle driver is not yet ready, right ? > >>>> > >>>>If it is the case, this driver is not needed yet, no ? > >>> > >>>The point of the patch is to allow the hardware drivers selected by > >>>CONFIG_ARCH_TEGRA to build for an arm64 kernel, just as they build for > >>>32-bit ARM. > >>> > >>>There's nothing CPUIdle-specific about the patch - that is, this timer= can > >>>be selected as a clockevent and clocksource provider without the use of > >>>CPUIdle - although low-power PM idle is likely to be a primary use-cas= e. > >> > >>What I meant is this timer is not needed for the moment. > >> > >>>>Perhaps you can rework a bit this driver in the meantime to have a be= tter fix > >>>>than disabling the code with macros ? > >>> > >>>I'm happy to do that, but it would be nice to get the driver compiling > >>>first for ARM64 :-) > >>> > >>>>Otherwise, please try at least to group the code into a minimal set o= f macros. > >>> > >>>So, would it be accurate to say that you would prefer a patch that cha= nges > >>>more lines of code, but minimizes preprocessor directives, to the curr= ent > >>>patch? > >> > >>Yes at least an attempt to factor out a bit the driver. Those #ifdef are > >>like #if 0, which is a quick fix. I am not strongly against this patch,= but > >>it would be nice to take the opportunity to reorganize it a bit. > > > >How about we do something like the attached patch instead for now. That > >avoids any #ifdef'ery and still we don't attempt (and fail) to build the > >driver on 64-bit ARM. > > > >With that applied we can incrementally make the changes to untangle the > >ARM-specific parts and when the driver can build on 64-bit ARM we simply > >select TEGRA_TIMER via Kconfig. >=20 > Yes, that is exactly what I was thinking about after sending the previous > email. And by this way, you also fixed the Kconfig option selection logic. Great. Will you give your Acked-by so that I can take that patch through the Tegra tree to resolve the build dependency? Thierry --9amGYk9869ThD9tj Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBAgAGBQJUr9i9AAoJEN0jrNd/PrOhlW0QAJ35JLPzCG6l4zNkyZk04T+u T51N6gToQk+BoeuEsLGsnI1KclFXTsrXIhvVhcd8mFLz4UGZB2GHfSOP2FV2WGqy V1PLBkI06l4P/a933nT7NY89LZgjwx/tc0kOG5H7Vp2DBmaaEICPN3y69FHpKwZt 70Uax1obJGtqwoeLmI0YIJZBXL9SRt7nt9LH/awJVNlpjFD3EIysX2W0BYLfmGcS ceG8qnDZF/4doN57QbjhdmS0EWPNTGqmv2eCroH6oN8Pqkic8Fk7QsAfQEnBVI7o pW49v7ZpX0ta4GdTK/AUiI5/H9yEJhoQQNVRV5cHMsDCmu2mhSgpP7H8g2LS2YZo y33xpEsPpRiTh8Hkt9bRUhezsz9CKdxh3Jh/NOzIA0iLItxr9HaFBoKjpIavlMN+ 9AX4RZNzjUUkLb9w5ZVHqm6LsnoPTwU2CtRJNKKpw0hryyMPXO7hbCxcDEolWswp /dpO59R7+JssZlQXd3lbtBSqpIfo21I5cE7ro+P+jPQk+XeXzwgBXqyZa0+/6JRZ UhhkCicEythsJYRrm4mgUHHUAvbs7i+E+tYlcKpyynflnD1vYofBx0Bmv919nR56 dwg9mG4cX9zu755McUoolXHSU+4pSRakJvtdxBfSNEfl03X7UaOWOK0PYBPY4I/v ayJShYr2edXPPwA2Y/I7 =i8VH -----END PGP SIGNATURE----- --9amGYk9869ThD9tj--