From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757492AbZBKA2T (ORCPT ); Tue, 10 Feb 2009 19:28:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755871AbZBKA2E (ORCPT ); Tue, 10 Feb 2009 19:28:04 -0500 Received: from kroah.org ([198.145.64.141]:50881 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755740AbZBKA2C (ORCPT ); Tue, 10 Feb 2009 19:28:02 -0500 Date: Tue, 10 Feb 2009 16:24:10 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Holger Macht , Len Brown Subject: [patch 01/56] ACPI: dock: Dont eval _STA on every show_docked sysfs read Message-ID: <20090211002410.GB14660@kroah.com> References: <20090211001439.873435357@mini.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="acpi-dock-don-t-eval-_sta-on-every-show_docked-sysfs-read.patch" In-Reply-To: <20090211002328.GA14660@kroah.com> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Holger Macht commit fc5a9f8841ee87d93376ada5d73117d4d6a373ea upstream. Some devices trigger a DEVICE_CHECK on every evalutation of _STA. This can also be seen in commit 8b59560a3baf2e7c24e0fb92ea5d09eca92805db (ACPI: dock: avoid check _STA method). If an undock is processed, the dock driver sends a uevent and userspace might read the show_docked property in sysfs. This causes an evaluation of _STA of the particular device which causes the dock driver to immediately dock again. In any case, evaluation of _STA (show_docked) does not necessarily mean that we are docked, so check with the internal device structure. http://bugzilla.kernel.org/show_bug.cgi?id=12360 Signed-off-by: Holger Macht Signed-off-by: Len Brown Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/dock.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/drivers/acpi/dock.c +++ b/drivers/acpi/dock.c @@ -691,8 +691,14 @@ fdd_out: static ssize_t show_docked(struct device *dev, struct device_attribute *attr, char *buf) { - return snprintf(buf, PAGE_SIZE, "%d\n", dock_present(dock_station)); + struct acpi_device *tmp; + struct dock_station *dock_station = *((struct dock_station **) + dev->platform_data); + + if (ACPI_SUCCESS(acpi_bus_get_device(dock_station->handle, &tmp))) + return snprintf(buf, PAGE_SIZE, "1\n"); + return snprintf(buf, PAGE_SIZE, "0\n"); } static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);