From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx49GaoFi4WnyuX7fMwU/MLkFDQ6+M2cHF3a19ViWQq+Y+4yVMFub8QuWq+TtnSDmsJuAmFLx ARC-Seal: i=1; a=rsa-sha256; t=1524598807; cv=none; d=google.com; s=arc-20160816; b=NliI59iv3S2f6HaawMtEus93mqvpVSFgAvBS2FkjgpCvbP2Zql1wX8wismnv1JOjd5 6qARMOT7Vd+wFjF1l5mRKjZB/Q8skAa59X9ShEbEq2I10bji71pnZJ24nLDwGHDSPnAz ePn8JQWvFippOg5oc+4GPOzUrgrnxvbG+c4E7tsaSzlIYe7Ynpq5o2VdJhztLAqSZZyL tzATXDvHQjNm7f/W+j/BR0fXKknqe8b1M4GhMVP4gQHOX9183SAYRPkv3/bA73xSgCAU QbCvxzTBLEYJN1r7YNO7yhK2qrgi1joJzXpepg7FTA65EsAT2i51xhMgUXze+us8/tl7 xyrQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=cc:to:subject:message-id:date:from:references:in-reply-to :mime-version:dmarc-filter:arc-authentication-results; bh=Z2X5BfjWJ/f6cPh5IZllg/EALVyg66CJygQrSIRYPTs=; b=nHpP5i64xqgeTNSncn9kRM+9DkIFhYpdaEndVxi3O1t23lhgAL8P0aeEptH/+WHtYQ g6MNwWtclUsP1+JEstR1QYZfxx7BmWyZ+2eqDTncWbbwVzpiIrW0VtKdvsdCDWlX+IFy lDromE3hHtkrm970nceUpSm9YkGvaTpLgsELVlrC/JpGGX0l1HoJk2W6eUYI/S9duYhK TdTBbxwRYhIrGbq+nq8X5B6r29kvbL3m2piz2BCdPXUTQTDUahjQSpo7YwT83pcWkTU4 qeRaLaVo5FvbkDc6TwmTTjB8ey9lY4dOOfYiIsYsTuSM/BhcE+7Wg3eFG+b5jI3oeWlt 6YnA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of robh+dt@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=robh+dt@kernel.org Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of robh+dt@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=robh+dt@kernel.org DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3E2B121774 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=robh+dt@kernel.org MIME-Version: 1.0 In-Reply-To: <20180424173051.15099-1-brgl@bgdev.pl> References: <20180424173051.15099-1-brgl@bgdev.pl> From: Rob Herring Date: Tue, 24 Apr 2018 14:39:44 -0500 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 00/11] platform: device tree support for early platform drivers To: Bartosz Golaszewski Cc: Sekhar Nori , Kevin Hilman , David Lechner , Michael Turquette , Stephen Boyd , Arnd Bergmann , Greg Kroah-Hartman , Mark Rutland , Yoshinori Sato , Rich Felker , Frank Rowand , "Rafael J . Wysocki" , Jarkko Sakkinen , Dmitry Torokhov , Arend van Spriel , Heikki Krogerus , Michal Suchanek , Jan Kiszka , Andy Shevchenko , "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" , "linux-kernel@vger.kernel.org" , devicetree@vger.kernel.org, Bartosz Golaszewski Content-Type: text/plain; charset="UTF-8" X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1598649607100825317?= X-GMAIL-MSGID: =?utf-8?q?1598657719313738135?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Tue, Apr 24, 2018 at 12:30 PM, Bartosz Golaszewski wrote: > From: Bartosz Golaszewski > > Device tree based systems often use OF_DECLARE() macros for devices > that need to be initialized early in the boot process such as clocks, > timers etc. However platform devices are more desirable. Yes, platform devices would be more desirable, but ... > > This series aims at introducing support for early platform drivers for > OF-based systems. ... the whole early_platform_device infrastructure is not really a platform_device. Rather it kind of looks like one and I guess gets converted over during boot. This is not the first attempt to add DT support to early platform devices[1]. I think the same objections still apply. It has been pretty much only an SH thing (which as an arch, I'm told is pretty much unmaintained and broken). > The idea is to have a special compatible fallback string: "earlydev" > that similarily to "syscon" would be added to device nodes that need > early probing. We then need to call of_early_platform_populate() early > in the boot process to actually probe the registered devices. Others have sufficiently explained why this won't fly for DT, so I don't have more to add. Rob [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2011-June/054529.html