From owner-freebsd-arch@FreeBSD.ORG Mon May 13 13:53:44 2013 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 16A46873 for ; Mon, 13 May 2013 13:53:44 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from mail-ia0-x233.google.com (mail-ia0-x233.google.com [IPv6:2607:f8b0:4001:c02::233]) by mx1.freebsd.org (Postfix) with ESMTP id DE0B6695 for ; Mon, 13 May 2013 13:53:43 +0000 (UTC) Received: by mail-ia0-f179.google.com with SMTP id h37so2342153iak.10 for ; Mon, 13 May 2013 06:53:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-received:sender:subject:mime-version:content-type:from :in-reply-to:date:cc:content-transfer-encoding:message-id:references :to:x-mailer:x-gm-message-state; bh=dkmwq4r6c0WTiQxJCoEWkN2iHv8+PjLXQ2mFlLbBtvQ=; b=VywBSzxDHqB2TZzg4Re+/jecSg4JULDaBXqslBC+4bM4dTfhgB+LKfJDBzUmkcZGcp 6Q1D83WLThAGwVxrPBRD48gcNRON90qf/OowxXLjCnPy6VHazyFzcmbdBChybhYB4qtR ptqbaAkzSs93DigGoNh4mYELTarhwD0nKPncNA3VYC0jh3QCmqTA3MkSX7NSPdsvdT9r QSIoLOYXbpvW/WuVS6yFdAvzG4cVRd5M2EQeWJCgJV4RqTOdeNoDDadO2e93rPotc7Du 5Ci2M71WPDNo/YCQkCQIvGtbJue1qtqpeO2Jjm4guMFkXbvgAChA8UwHpefu2QaP5F6V 8C0g== X-Received: by 10.42.84.201 with SMTP id n9mr12526247icl.47.1368453223441; Mon, 13 May 2013 06:53:43 -0700 (PDT) Received: from 53.imp.bsdimp.com (50-78-194-198-static.hfc.comcastbusiness.net. [50.78.194.198]) by mx.google.com with ESMTPSA id xf4sm17265568igb.8.2013.05.13.06.53.41 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 13 May 2013 06:53:41 -0700 (PDT) Sender: Warner Losh Subject: Re: late suspend/early resume Mime-Version: 1.0 (Apple Message framework v1085) Content-Type: text/plain; charset=us-ascii From: Warner Losh In-Reply-To: Date: Mon, 13 May 2013 07:53:39 -0600 Content-Transfer-Encoding: quoted-printable Message-Id: References: To: Justin Hibbits X-Mailer: Apple Mail (2.1085) X-Gm-Message-State: ALoCoQklLNptU1b8koQstldcU3ZmcjN1P4KfFRVeitocFN/kKZWqD+j20iZ7VA8lXplQJObOEPOB Cc: freebsd-arch@freebsd.org X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 May 2013 13:53:44 -0000 Where is the northbridge in the object tree hierarchy? Since you are asking this, I'm guessing it isn't at the top of the tree, = and can't easily be. I don't like this idea. I think it is is silly and will lead only to = additional proliferation of late late late early late calls. Much better would be for the suspend routine to return a number = indicating how late to be called (and correspondingly how early resume = should be called). this way the tree walking code can insert these = devices into an ordered list that can then be walked at the end of = suspend and traversed backwards at the start of resume. There are many embedded systems where there's a bit of a partial = ordering between clock generation blocks and power blocks that need to = be handled specially since there's no ACPI on those platforms to do = things last. We don't model them well at all (or even at all), and = having some mechanism in place to help with that would be useful. So in short I understand the need, but feel that the kobj extensions you = propose are little better than the hard-coded calls and would like to = see something a little more generic since the in-order traversal of the = device tree seems a poor fit to 'special cases' like this. Warner On May 13, 2013, at 1:20 AM, Justin Hibbits wrote: > I'd like to solicit opinions on adding new kobj device API calls, > device_late_suspend and device_early_resume. >=20 > I've been working on PowerPC suspend/resume, and certain devices must = be > suspended last and resumed first on Apple hardware, namely the = chipsets. > It happens that one device (uninorth) appears first in the devinfo = chain, > while the other (mac-io) appears off a later PCI bus. So, rather than > special casing this to suspend the mac-io and its children, as well as = the > uninorth, last with specific calls, I'd like to add a = device_suspend_late > and device_resume_early, that would simply be identical to > device_suspend/device_resume, but could be called after and before, > respectively, to do last minute order suspend and first pass > initialization, to initialize things like clocks required for other = devices. >=20 > It's not difficult to explicitly call suspend and resume functions on = the > chipsets, but I think it's cleaner to do it through the newbus/kobj > interface, and it might be useful for other architectures as well. >=20 > Thoughts? >=20 > - Justin > _______________________________________________ > freebsd-arch@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-arch > To unsubscribe, send any mail to = "freebsd-arch-unsubscribe@freebsd.org"