From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [GIT PULL] On-demand device probing To: Tim Bird , "frowand.list@gmail.com" , Greg Kroah-Hartman References: <20151018192931.GY14956@sirena.org.uk> <20151018193757.GA9147@kroah.com> <20151018195330.GB14956@sirena.org.uk> <5627B677.5090109@gmail.com> <20151021162758.GP32054@sirena.org.uk> <5627D6E0.5020708@gmail.com> <562808AF.7090406@gmail.com> <20151022144405.GC21861@kroah.com> <562930AB.1070203@gmail.com> <562A5602.7000208@sonymobile.com> CC: Tomeu Vizoso , Rob Herring , Mark Brown , Russell King , Michael Turquette , Stephen Boyd , Vinod Koul , Dan Williams , Linus Walleij , Alexandre Courbot , Thierry Reding , David Airlie , =?UTF-8?Q?Terje_Bergstr=c3=b6m?= , Stephen Warren , Wolfram Sang , Grant Likely , Kishon Vijay Abraham I , Sebastian Reichel , Dmitry Eremin-Solenikov , David Woodhouse , Liam Girdwood , Felipe Balbi , Jingoo Han , Lee Jones , Jean-Christophe Plagniol-Villard , Tomi Valkeinen , "linux-kernel@vger.kernel.org" , "linux-clk@vger.kernel.org" , "dmaengine@vger.kernel.org" , "linux-gpio@vger.kernel.org" , "dri-devel@lists.freedesktop.org" , "linux-tegra@vger.kernel.org" , "linux-i2c@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-pm@vger.kernel.org" , Linux PWM List , "linux-usb@vger.kernel.org" , "linux-fbdev@vger.kernel.org" From: "Andrew F. Davis" Message-ID: <562D3172.2070303@ti.com> Date: Sun, 25 Oct 2015 14:45:54 -0500 MIME-Version: 1.0 In-Reply-To: <562A5602.7000208@sonymobile.com> Content-Type: text/plain; charset="windows-1252"; format=flowed List-ID: On 10/23/2015 10:45 AM, Tim Bird wrote: > I've been worried about DT overhead adding to boot time for a while. > And IMHO probe deferral is just about the lamest way to solve boot > order dependencies I can imagine, from a computer science perspective. > (Well, there's a certain elegance to it, but it's a stupid "make > everything re-doable, back up and start over, time-wasting" elegance.) > It has a bogosort kind of elegance. :) Also this might be a silly question (I haven't been following this issue for very long), but as the only place that can really know what devices depend on each other, in a generic kernel, is the DT (or whatever abstraction) will we not eventually need to solve this issue there? Could we just add a "depends-on = <&phandle>;" to nodes when we know they are needed for our board?