Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752753Ab3HDNxR (ORCPT ); Sun, 4 Aug 2013 09:53:17 -0400 Received: from hydra.sisk.pl ([212.160.235.94]:55101 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751680Ab3HDNxP (ORCPT ); Sun, 4 Aug 2013 09:53:15 -0400 From: "Rafael J. Wysocki" To: Toshi Kani Cc: ACPI Devel Maling List , LKML , Bjorn Helgaas Subject: Re: [PATCH] ACPI: Do not fail acpi_bind_one() if device is already bound correctly Date: Sun, 04 Aug 2013 16:03:27 +0200 Message-ID: <1981183.omDzKl0aqK@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.10.0+; KDE/4.9.5; x86_64; ; ) In-Reply-To: <1375576322.10300.146.camel@misato.fc.hp.com> References: <1888947.F5IBMfDKlY@vostro.rjw.lan> <3596381.TNBAQz9C67@vostro.rjw.lan> <1375576322.10300.146.camel@misato.fc.hp.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1926 Lines: 43 On Saturday, August 03, 2013 06:32:02 PM Toshi Kani wrote: > On Sat, 2013-08-03 at 02:47 +0200, Rafael J. Wysocki wrote: > > On Friday, August 02, 2013 04:38:38 PM Toshi Kani wrote: > > > On Fri, 2013-08-02 at 00:33 +0200, Rafael J. Wysocki wrote: > > > > From: Rafael J. Wysocki > > > > > > > > Modify acpi_bind_one() so that it doesn't fail if the device > > > > represented by its first argument has already been bound to the > > > > given ACPI handle (second argument), because that is not a good > > > > enough reason for returning an error code. > > > > > > While it seems reasonable to allow such case, I do not think we will hit > > > this case under the normal scenarios. So, I do not think we need to > > > make this change now unless it actually solves Yasuaki's issue (which I > > > am guessing not). > > > > In theory it should be possible to call acpi_bind_one() twice in a row > > for the same dev and the same handle without failure, that simply is > > logical. The patch may not fix any problems visible now, but returning an > > error code in such a case is simply incorrect. > > We changed acpi_bus_device_attach() to not call the handler or driver > again if it is already bound. So, I was under impression that we > prevent from attaching a same device twice. But I may be missing > something... acpi_bind_one() may be called in code paths that don't start from acpi_bus_device_attach(), like acpi_platform_notify(), where the result depends on how .find_device() is implemented by the the given bus type, for example. Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/