From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Brownell Subject: Re: [patch 2.6.25-rc6 1/7] crosslink ACPI and "real" device nodes Date: Fri, 21 Mar 2008 02:04:15 -0700 Message-ID: <200803210204.15843.david-b@pacbell.net> References: <200803201408.33466.david-b@pacbell.net> <200803210031.35174.david-b@pacbell.net> <1206088471.4109.56.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from smtp122.sbc.mail.sp1.yahoo.com ([69.147.64.95]:38233 "HELO smtp122.sbc.mail.sp1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752007AbYCUJES (ORCPT ); Fri, 21 Mar 2008 05:04:18 -0400 In-Reply-To: <1206088471.4109.56.camel@localhost.localdomain> Content-Disposition: inline Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Zhao Yakui Cc: linux-pm@lists.linux-foundation.org, Thomas Renninger , linux-acpi@vger.kernel.org On Friday 21 March 2008, Zhao Yakui wrote: > On Fri, 2008-03-21 at 00:31 -0700, David Brownell wrote: > > > > The PNP device gets a "firmware_node" link pointing to the ACPI= device. > > > > The ACPI device has a "physical_node" link pointing to the PNP = device. > > > > Linux drivers currently bind only to the "physical" device node= s. > > > =20 > > > Very good idea.=20 > > > But maybe there is a lot of ACPI devices on the laptops. And we t= ake a > > > little care about the association between the acpi device and "re= al" > > > device. > >=20 > > Are you suggesting that the ACPI nodes shouldn't exist at all? > > Or that something is wrong with how they're set up or used? >=20 > No. The ACPI nodes should exist. What I said is whether it is necessa= ry > to create the link for all the ACPI devices between the ACPI device a= nd > "real" node device. Of course it is also OK if link is created for t= he > ACPI device with the ability to wake the sleeping system.=20 The confusion exists for all ACPI device nodes that mirror "real" device nodes (like PNP or PCI devices). It's *not* limited to wake-capable devices. > > For now, there's some confusion. =A0Devices listed in ACPI tables > > have one or two extra sysfs device nodes. =A0I think *something* > > should help sort out the confusion ... (Minor correction: *most* devices listed in ACPI tables have the problem of extra sysfs nodes. A few don't; like buttons.) > Sorry. What I means is that the link(point to the ACPI device with th= e > ability to wake the sleeping system) is created in the /sys/power/.=20 > After doing so, we can easily check which device has the ability to w= ake > the sleeping system.=20 There's no need for symlinks to do that ... or ACPI. I've been meaning to repost my script that scans sysfs for the wakeup-capable devices ... I updated it a short while ago to work right without "legacy" sysfs nodes. - Dave -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html