From owner-freebsd-arch@FreeBSD.ORG Fri May 24 15:08:23 2013 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id 30528D15; Fri, 24 May 2013 15:08:23 +0000 (UTC) (envelope-from chmeeedalf@gmail.com) Received: from mail-bk0-x22f.google.com (mail-bk0-x22f.google.com [IPv6:2a00:1450:4008:c01::22f]) by mx1.freebsd.org (Postfix) with ESMTP id 8B2A7827; Fri, 24 May 2013 15:08:22 +0000 (UTC) Received: by mail-bk0-f47.google.com with SMTP id jg1so2566200bkc.34 for ; Fri, 24 May 2013 08:08:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; bh=4TgIgd8nTBy827rsFNp88qxMZzVtw1zvVkzcPSTWaLw=; b=ZZlMacLNoWCqK1yHf3DQO2EnmPfKBmnhYID76K7VrEP6WUyjDFmrbTYbLJzSTJvWcr com78M1FcMPuGk63QiTi+PoKJPvv2WBjWIJzICDND+HizVrKfgkDwcN2GnDD+Y001gTQ 7Z5WoD9DTDhZdADsrS9I5VDVx391UsKynyRTdFy6nnrtjn++cat9XjACUatlUWs5jAxz DW+/of/o4H07h6QVpWjok+jHEJHv0U7PkS3c14K6Ezc67GL8HZWs5rOiWPxY0JO2uUY9 btB2M5kgdesvQl1NhWohc7RIvJZVFWzEnv6IA2c7Fk2QDVF6Xgl7meJ6Gh83nLd9fmPT hxvA== MIME-Version: 1.0 X-Received: by 10.204.65.69 with SMTP id h5mr9399810bki.59.1369408101489; Fri, 24 May 2013 08:08:21 -0700 (PDT) Sender: chmeeedalf@gmail.com Received: by 10.204.38.144 with HTTP; Fri, 24 May 2013 08:08:21 -0700 (PDT) In-Reply-To: <780B27A1-AA4F-4382-BE33-7587BD9EB615@bsdimp.com> References: <51913B7D.1040801@freebsd.org> <288C9B9E-E943-4C5B-BCFB-15B721CBE94C@bsdimp.com> <519369C4.6060402@FreeBSD.org> <780B27A1-AA4F-4382-BE33-7587BD9EB615@bsdimp.com> Date: Fri, 24 May 2013 08:08:21 -0700 X-Google-Sender-Auth: p3uyIJDf3JYtS_b0LSK7Z1MHxJw Message-ID: Subject: Re: late suspend/early resume From: Justin Hibbits To: Warner Losh Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.14 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: Fri, 24 May 2013 15:08:23 -0000 On Thu, May 23, 2013 at 10:11 PM, Warner Losh wrote: > > On May 23, 2013, at 11:08 PM, Justin Hibbits wrote: > > > John, > > > > > > On Wed, May 15, 2013 at 3:56 AM, John Baldwin wrote: > > > >> On 5/14/13 1:14 PM, Justin Hibbits wrote: > >>> You are right that the late suspend could lead to silly proliferation, > >> and > >>> an ordered list is much better, but another API would need to be added > to > >>> do that as well. > >>> > >>> My north bridge is first in the top list of the tree, right under the > >>> nexus, so to suspend it last I wrote the nexus suspend to traverse its > >>> children in reverse. The problem comes that the clock controller is > >> under a > >>> later PCI bus, not even the immediate following one, and the north > bridge > >>> children are i2c devices, so suspending them after their clock head > away > >> is > >>> problematic. We can discuss this more at bsdcan, where it may be > easier > >> to > >>> describe. But essentially I need the north bridge and that pesky clock > >>> controller to be the last to suspend and the first to resume. I guess > we > >>> can take this as the starting discussion for modeling this relationship > >> on > >>> all platforms, since you mention it is common in embedded platforms. > >> > >> I think you can do this by having a notion of passes with drivers having > >> a suspend pass level and doing passes over the tree suspending devices > >> at each pass level and then walking the passes back up in reverse during > >> resume. You could borrow from the multipass stuff used on probe/attach > >> for this. > >> > >> -- > >> John Baldwin > >> > > > > I have an update in the projects/pmac_pmu branch. It works for my > > PowerBook, but I'm not certain how well it will fare in the end, because > of > > the way the PCI driver resumes its children. It doesn't call > > bus_generic_resume(), and instead suspends each child individually, which > > can lead to devices being resumed multiple times, but I'm uncertain how > to > > fix that. Any ideas? One I had was to have some kind of > > 'bus_generic_resume_filtered' or similar, that lets bus_generic_resume > run > > its logic, but filter through a function to determine if the child is > > resumable. But that doesn't quite feel right to me. > > How does it lead there? Did you change the suspend/resume function > signatures? Or did you create new ones like I suggested that had a default > method that called the old suspend/resume function iff pass was the last > one.... > > > Warner > > I must've misunderstood you during our discussion. I simply reused the existing bus_generic_suspend/resume, and used EAGAIN to pass a token of 'rescan this again'. - Justin