From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763775AbXK2Xk4 (ORCPT ); Thu, 29 Nov 2007 18:40:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762939AbXK2Xkn (ORCPT ); Thu, 29 Nov 2007 18:40:43 -0500 Received: from g1t0028.austin.hp.com ([15.216.28.35]:49047 "EHLO g1t0028.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756626AbXK2Xkm (ORCPT ); Thu, 29 Nov 2007 18:40:42 -0500 From: Bjorn Helgaas To: Andrew Morton Subject: Re: WARNING: at kernel/resource.c:189 __release_resource Date: Thu, 29 Nov 2007 16:40:37 -0700 User-Agent: KMail/1.9.6 Cc: Jiri Slaby , Matthew Wilcox , Linux kernel mailing list , Greg KH , linux-usb-devel@lists.sourceforge.net, linux-pm@lists.linux-foundation.org, Pierre Ossman References: <4745F77C.7040402@gmail.com> <20071126220538.1aed9c33.akpm@linux-foundation.org> In-Reply-To: <20071126220538.1aed9c33.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200711291640.38158.bjorn.helgaas@hp.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Monday 26 November 2007 11:05:38 pm Andrew Morton wrote: > On Thu, 22 Nov 2007 22:41:16 +0100 Jiri Slaby wrote: > > Ok, I hit the bug, suspend of 00:06 device complains about it: > > WARNING: at .../kernel/resource.c:185 __release_resource() > > > > Call Trace: > > [] release_resource+0xb5/0xf0 > > [] pnp_release_resources+0x70/0x130 > > [] pnp_stop_dev+0x45/0x90 > > [] pnp_bus_suspend+0x92/0xb0 > > [] suspend_device+0x113/0x180 > > [] device_suspend+0x200/0x320 > > [] suspend_devices_and_enter+0xa5/0x170 > > [] enter_state+0x209/0x270 > > [] state_store+0xaf/0xf0 > > [] kobj_attr_store+0x17/0x20 > > [] sysfs_write_file+0xce/0x140 > > [] vfs_write+0xc7/0x170 > > [] sys_write+0x50/0x90 > > [] system_call+0x7e/0x83 > > > > # LANG=en ll /sys/devices/pnp0/00:06/ > > total 0 > > lrwxrwxrwx 1 root root 0 Nov 22 22:35 driver -> ../../../bus/pnp/drivers/serial > > -r--r--r-- 1 root root 4096 Nov 22 22:35 id > > -r--r--r-- 1 root root 4096 Nov 22 22:35 options > > drwxr-xr-x 2 root root 0 Nov 22 22:35 power > > -rw-r--r-- 1 root root 4096 Nov 22 22:35 resources > > lrwxrwxrwx 1 root root 0 Nov 22 22:35 subsystem -> ../../../bus/pnp > > drwxr-xr-x 3 root root 0 Nov 22 22:35 tty > > -rw-r--r-- 1 root root 4096 Nov 22 22:35 uevent > > I suppose that's a genuine leak, presumably in 8250_pnp. We used to have only the serial driver resource reservation. We now have an additional 00:06 resource that is the parent of the serial resource, e.g., 03f8-03ff : 00:06 03f8-03ff : serial I think this problem happens because pnp_bus_suspend() calls serial_pnp_suspend(), which suspends the driver but does nothing with the resources. Then it calls pnp_stop_dev(), which releases the 00:06 resource, which still has a serial child resource. The corresponding PCI code in pci_device_suspend() does not do any generic device disable or resource release. I don't know why PNP disables the device on suspend. I glanced through the ACPI spec but didn't see a requirement for it. Maybe Pierre [1] remembers. Maybe we could either remove the pnp_{stop,start}_dev() calls from the suspend/resume path, or move the PNP resource management out of pnp_{start,stop}_dev(). Bjorn [1] http://lkml.org/lkml/2005/11/30/39