From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx177.postini.com [74.125.245.177]) by kanga.kvack.org (Postfix) with SMTP id 048D26B0005 for ; Mon, 4 Feb 2013 07:27:46 -0500 (EST) From: "Rafael J. Wysocki" Subject: Re: [PATCH?] Move ACPI device nodes under /sys/firmware/acpi (was: Re: [RFC PATCH v2 01/12] Add sys_hotplug.h for system device hotplug framework) Date: Mon, 04 Feb 2013 13:34:02 +0100 Message-ID: <2107169.R5mOc9qh97@vostro.rjw.lan> In-Reply-To: <20130204012447.GB6433@kroah.com> References: <1357861230-29549-1-git-send-email-toshi.kani@hp.com> <2806030.VWUMy6F7lm@vostro.rjw.lan> <20130204012447.GB6433@kroah.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: owner-linux-mm@kvack.org List-ID: To: Greg KH Cc: Toshi Kani , lenb@kernel.org, akpm@linux-foundation.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, bhelgaas@google.com, isimatu.yasuaki@jp.fujitsu.com, jiang.liu@huawei.com, wency@cn.fujitsu.com, guohanjun@huawei.com, yinghai@kernel.org, srivatsa.bhat@linux.vnet.ibm.com On Sunday, February 03, 2013 07:24:47 PM Greg KH wrote: > On Sat, Feb 02, 2013 at 11:18:20PM +0100, Rafael J. Wysocki wrote: > > On Saturday, February 02, 2013 09:15:37 PM Rafael J. Wysocki wrote: > > > On Saturday, February 02, 2013 03:58:01 PM Greg KH wrote: > > [...] > > > > > > > I know it's more complicated with these types of devices, and I think we > > > > are getting closer to the correct solution, I just don't want to ever > > > > see duplicate devices in the driver model for the same physical device. > > > > > > Do you mean two things based on struct device for the same hardware component? > > > That's been happening already pretty much forever for every PCI device known > > > to the ACPI layer, for PNP and many others. However, those ACPI things are (or > > > rather should be, but we're going to clean that up) only for convenience (to be > > > able to see the namespace structure and related things in sysfs). So the stuff > > > under /sys/devices/LNXSYSTM\:00/ is not "real". In my view it shouldn't even > > > be under /sys/devices/ (/sys/firmware/acpi/ seems to be a better place for it), > > > but that may be difficult to change without breaking user space (maybe we can > > > just symlink it from /sys/devices/ or something). And the ACPI bus type > > > shouldn't even exist in my opinion. > > > > Well, well. > > > > In fact, the appended patch moves the whole ACPI device nodes tree under > > /sys/firmware/acpi/ and I'm not seeing any negative consequences of that on my > > test box (events work and so on). User space is quite new on it, though, and > > the patch is hackish. > > Try booting a RHEL 5 image on this type of kernel, or some old Fedora > releases, they were sensitive to changes in sysfs. Well, I've found a machine where it causes problems to happen. I'll try to add a symlink from /sys/devices to that and see what happens then. Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org